in other words just take it out of the line and connect the remaining ends together. have the same problem? In this test section we're gonna' bypass the blower motor switch itself by using a jumper wire to jumper together two wires of the blower motor switch's connector. Do you. You'll be able to test the blower motor switch, with the help of this tutorial, and find out if it's bad or not. It's possible to reset the switch at home when necessary by following a few simple steps. Reactions: BB Benz and jwight. A Convection Fan Switch is usually mounted to the back of the firewall of the pellet stove and has two wires going to it. The best suspect for that is the motor itself. The switch activates with air force pushing a plunger in the mechanism, which closes the circuit.Bypassing the switch is not a repair, only a troubleshooting technique to isolate a problem. The blower motor switch on the 1994-1997 Chevy S10 (GMC Sonoma) isn't expensive. For this reason, if you suspect that your blower motor switch has a problem or fault, have the vehicle’s AC system diagnosed by a professional technician, such as one from YourMechanic. I (and my furnace maintenance company) have tried reseating the door and duct taping the switch down, which solves the problem for a few weeks, but then it returns I'm tired of dealing with this problem and am considering bypassing the blower door switch. Save Share. Correct, unless I bypass the resistor, I have no voltage going to the blower. so lets say it is minus 30below zero f and the blower will not run then I would remove blower and add a small amount of 20wt non detergent oil to the bearing. ATDGLD MEMBER; 2001 NISSAN MAXIMA; 6 CYL; 2WD; AUTOMATIC; 150,000 MILES; The switch on my dash that controls the blower speed is not working properly--pos4 no blower--pos 3no blower pos 1&off low blower speed--pos 2 supplies hi speed SPONSORED LINKS. Power for the HVAC operating unit comes from SAM 10A fuse #20. Remove the cover by lifting it upwards or pulling it off to reveal the body of the switch and two metal arms. Disconnect the blower motor switch from its connector. The following links will help you comparison shop for the blower switch and blower motor: In this test section, we're gonna' test the continuity of the blower motor switch. Depending on your furnace model, the switch will be surrounded by a silver or white cover. Jeep  |   Late 1997 S10 use a different blower motor switch. Place your multimeter in Ohms mode. If your switch melted the motor may be worn out and drawing too much current. Some common signs of a broken blower motor switch are if the switch only works on certain air settings, which occurs when a contact wears out, or if the switch is stuck or often gets stuck, indicating that the switch is not working properly. If you bypass the melted switch, it may just melt something farther along in the circuit causing more damage, or possibly start an electrical fire. For a better experience, please enable JavaScript in your browser before proceeding. The blower motor fan in my 1992 Dodge Dakota LE 3.9L does not work. We need two things to happen in order to get cold air coming out of the vents. JavaScript is disabled. GM  |   2 each – SPDT (on/off/on) Gardner Bender toggle switch wire, motor, and appropriate electrical housing w/ cover. Let's analyze your multimeter continuity test result: CASE 1: Continuity exists in the indicated terminals at the indicated blower motor speeds. Ford  |   Any help will be appreciated. Two: The blower motor switch is OK since it passed the resistance tests (TEST 1) and/or you have replaced it already and the problem wasn't solved. Locate the white limit switch. Place the blower control switch lever in the M1 speed position. How to Identify a Failing Blower Motor Relay. Copyright © 2009-2020 Abraham Torres-Arredondo All Rights Reserved. level 1. The resister was replaced, that did not do it. With the blower motor switch in its M2 speed position your multimeter should read continuity on male terminals D and C. We have a modern furnace with an old thermostat that controls heat and has a wire pair traveling to the furnace's control board. Bad electric motor start switch: The electric motor will overheat if the start-switch does not disconnect at the proper or "throwout" rpm. For Wes, a more common cause of an inoperative blower is poor contact of the motor brushes to the commutator. You don't need to remove the switch from the AC Heater Control Panel. 2 Replies 1 Participant Last post: Jcjetty Apr 24, 2017. Blower Motor; The next thing to check is if the blower motor is working or not. Ok, how to bypass a circuit board that is fried. Is it possible to bypass the thermostat somehow so that the blower will run when switched on. One way to check this is to go to the thermostat and turn the FAN setting from AUTO to ON. Weak Blower Motor – Sometimes the blower motor fails. 102 degrees in Texas heat is no fun. If you know of a more elegant way, feel free to post it in the comments below. The control voltage varies the conductivity of a 2SD1297 Darlington Bipolar Junction Transistor (G50 version), or a 2SK2500 MOSFET Power Transistor (Y33 version) which is connected in series with the blower motor – When … Blower Motor Switch Basics. If the blower motor is not working and no air is being blown through the unit it will overheat and the high limit switch will turn the gas off. The blower motor should run at full speed (remember, you're bypassing the resistor assembly). You don't need to remove the switch from the AC Heater Control Panel. I've traced the problem to the blower door switch. The blower motor resistor is responsible for controlling the blower motor speed. To be sure, I suggest doing one more test and it's to bypass the switch itself. Blower Switch on A/C Heater Control Panel. buy new blower motor put in the cold see if it rotates like the old one. Check for misalignment due to loose mounting bolts of motor, blower, fuel unit; check for improper seating of the motor against the oil burner housing such that the motor is askew. For a automatic climate control system. I think I may have loosened a wire in the area of the thermostat. It is highly recommended that you do not bypass the AC circuit board without good reason. Save Share. With that said, failed blower resistor assemblies don't solve all of the possible failures. As you bypass each blower speed, the blower motor should run if everything is OK. Here's the current wiring feeding down into the PCB input terminals . The switch and resistor are in the ground circuit. If you've got excessive noise coming from your dash, you might also have debris inside your blower motor. 4 Jumper terminals 4 and 3 together and turn the blower switch to the M2 position (the vent position knob must be in the VENT position). Video demonstrating the standard wiring for the primary blower motor found in most furnaces and air handlers in residential HVAC. Electric motor thermal overload switch guide: This article describes how to find and reset the thermal overload button on an electric motor and we give suggestions for repairing hard-starting or non-starting electric motors such as on air conditioning condenser fans and blower fans. Second, we need the blower motor on. The switch is normally Off or Open and turns on when the stove gets hot enough which turns on the convection fan. It's a really simple circuit. It's important to note that what we're looking for, on the digital multimeter reading, is a non-OL reading. Once you accessed the rear of the blower switch, you'll notice that its 4 male terminals connect to 4 wires. Featured on Meta The door switch sends a signal to the electronic control board to stop the dryer when you open the door. Chrysler  |   My brother in law came over took found a loose wire and hooked it back up, but the blower still won't come on. This jumper wire will take the place of the blower switch and depending on what two terminals we jumper together, you'll get the blower motor to produce M1, M2 or HI speed. To restore the furnace to normal operation, you must reset the switch on the blower motor. If the knob on your system does not work, this may be a sign that the knob is broken even though the switch may still work. The blower motor now runs in M2 speed. To get the lower speeds with the blower motor they use the blower motor resistor, the highest setting will use the full circuit voltage, normally around 12 volts and the slower you get the more resistance is applied and the lower the voltage gets to the blower motor. they call me the workin' man, I gues that's what I am..." Rush ‘Working Man’, Home  |   The resister was replaced, that did not do it. with the hvac blower on max NO RESISTORS . Honda  |   Re-mount. Essentially an on/off switch, the blower motor relay’s reactions start and end the heating process in HVAC systems by controlling the flow of current between the power source and the motor. One hot (12v) a center wire ? An aging, problematic, or dirty motor has to work harder to properly circulate conditioned air throughout your home, which leads to higher energy consumption. Join the discussion. The pressure switch on a Lennox G16 gas furnace monitors whether the air blower is in operation. This high power causes a short circuit and burns out the circuit board. Step 1. Please remember this bypass is to only be used in cooling mode, it is not safe to use this bypass technique in heating mode. You just need a connection from the rheostat to the motor. I'm not exactly sure of what you are talking about. I just don't want to blow anything up. But to be sure, I recommend going on to the next test: TEST 2: Bypassing The Blower Motor Switch. The blower motor is the part of your HVAC system that uses the most energy, so it may very well be the culprit if you see a significant rise in your utility bills. Also, I'm afraid I may have damaged these two wires when I was cleaning. Monday, June 14th, 2010 AT 10:25 … Ford blower motor resistor problems remain the most common solution to interior fan malfunctions on Ford cars and trucks. Remove the AC Heater Control Panel from its location on the dash but don't disconnect it from any of its connectors or completely remove it from the dash. Most Convection Fan Switches turn on/off at 200 degrees Fahrenheit. This material may not be reproduced without the author's consent. Run a fused jumper from the battery to the power side of the motor and connect a temporary grounding jumper to the other motor terminal. It seems to me I could live my life a lot better than I think I am. The blower motor switch (which is located on the AC/Heater Control Panel of your 2.5L Ford Ranger) is the one that lets you choose the blower motor speed. As an Amazon Associate, I may earn a small commission from qualifying purchases from the Amazon product links from this website. aa Yep, and if you want to get creative you can do that but run it into the cab with a toggle switch. For this test go to: TEST 2: Bypassing The Blower Motor Switch. CASE 2: Continuity DOES NOT exist between two indicated terminals. Disconnect the blower motor switch from its connector. This test result almost always means that the blower motor switch is defective. Hi I have a 2000 E430 and I've had a lot of issues with the blower motor resistor/regulator, And at this point I'm sick of it and I need my AC. Reply. En Español  |   For the most part, a continuity reading tells you that the blower motor switch IS NOT defective. Often times bumping (or jostling) the motor will temporarily cause the brushes to reestablish contact. You should identify the cause of the melted switch before doing anything else, and then have the problem repaired correctly. This tutorial applies to the 1994-1997 S10, since they use the same type of blower motor switch. It now does not work again. Power Tip - The blower motor resistor produces heat when in operation. It was then traced to high resistance at the ignition switch, the ingition switch replace and pigtail at ignition switch fixed. In respect to this, can I bypass pressure switch on furnace? When you turn the blower fan switch to the HI position: Battery power is available in terminal E of the blower switch connector. Problem it was in the vent switch! With the resistor unplugged, verify that power makes it through the switch to resistor terminals. A door switch is a simple on/off mechanism that prohibits the dryer from operating when the door is open. see if it works. Thanks Mike. The blower motor relay supplies power to this motor when you turn the switch to "on" that can sometimes fail. I'd like to wire up a local light switch by the furnace to manually turn on the blower fan to do some extra filtration of the air in the interior of the home. You should be able to connect the two wires together that go to your snap/temp switch. How To Test The Fuel Pump (2005-2006 2.2L Chevrolet Cobalt), How To Test The MAP Sensor (2007-2010 2.2L Chevrolet Cobalt), How To Test The MAP Sensor (1998-2005 2.2L Chevrolet Cavalier), "I get up at seven, yeah, and I go to work at nine. Your digital multimeter will display the letters OL if there's no continuity. The interior fan is powered through two separate fuses and a blower motor relay. Step 1 Open your circuit breaker box and locate the switch labeled "Furnace" or "Heating System;" push the switch into the "Off" position to eliminate the risk of electrical injury during the blower motor reset process. Misc Index  |   This may also cause the blower motor to work intermittently. Page 2 of 2: How to Test the Blower Motor Switch (Ford 4.6L, 5.4L). Two-speed motors use a switch oriented towards either high speed or low speed coil. This should make your blower work all the time. 6. HOW IT WORKS: The Fan Control Amp receives a control voltage from Pin 35 of the AC Auto Amp; this voltage varies depending on howmuch blower motor speed is desired. Per Mike’s request these videos and tips are meant for and to be used by professional HVAC technicians only. Thanks, Robbie. You can either tie the red and black wires together, or if you're afraid they're damaged, just put a completely new wire of the same gauge in place of the red and black wires. I got no time for livin'... yes, i'm workin' all the time. You would hook the hot wire usually black (high speed) on the blower to the black wire of a stripped extension cord with a wire nut then hook the white (neutral wire) of your blower motor to the white wire of the extension cord and plug the extension cord into a 120-volt outlet. If you have a variable speed blower motor system: Disconnect the electrical connector at the blower motor and jumper power and ground to the motor, bypassing all the speeds controls. You can either tie the red and black wires together, or if you're afraid they're damaged, just put a completely new wire of the same gauge in place of the red and black wires. Using the illustration above, these blower speeds are: LO, M1, M2, and HI. 1 - 3 of 3 Posts. Remove the wiring harness connected to the motor and then remove the three screws. It has 3 wires. Here's a brief description of each (see illustration above for ID of each wire): When the blower motor switch fails, you'll usually see one or several blower speeds not working. It will be located at the top of the panel. Your purchase helps support my work in bringing you real diagnostic testing information to help you solve the problem on your vehicle. Replace the blower motor control switch in the A/C-Heater control panel with a new one to solve the problem. I guess that's why they call me, Nissan  |   The interior fan is powered through two separate fuses and a blower motor relay. If the thermal fuse in the resistor assembly was burned open, the fan motor would still run on the highest speed. If you believe my way will be my doom, well I'm here writing about aren't I? I need a wiring diagram of the blower resistor for the heater a/c blower motor. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register. Power for the blower motor comes from the SAM 25A fuse #4. In the past, this was done by varying the voltage supplied to the blower motor. Lift the control panel off the front of the furnace. In order to get cold air, while waiting on the part. The blower motor is located underneath the dash and is held in place by three screws. For this reason, if you suspect that your blower motor switch has a problem or fault, have the vehicle’s AC system diagnosed by a professional technician, such as one from YourMechanic. When this happens, you may notice that you will not feel anything blowing out of the vents at all. This is why at the bottom of the article we include a 2008 F150 blower motor wire diagram. You just need a connection from the rheostat to the motor. Thanks. Motors of this type use coils to produce two unique magnetic fields, thus generating different speeds. 4 Jumper terminals B and A together (this is the circuit that controls blower speed M2). These resistors commonly become corroded or simply break after being exposed to high voltage over time. You should be able to simply run a hot wire to the blower motor. The Hearth Room - Wood Stoves and Fireplaces. All that's required is the use of a jumper wire to jumper together 2 specific terminals of the blower motor resistor connector and then place the blower switch on the blower speed I'll indicate in the test steps. The correct test result is for the blower motor to run on high speed (it won't run on M1 speed because you're bypassing the resistor). VW  |   Actually, the last post from marky mark sounds like what I want to do. The next step is to bypass the blower switch using a small jumper wire and indirectly test the wiring and blower resistor between the … Place your multimeter in Ohms mode. Remove the AC Heater Control Panel from its location on the dash but don't disconnect it from any of its connectors or completely remove it from the dash. Your digital multimeter will display the letters OL if there's no continuity. The blower switch now opens the contacts for terminal E and C. The blower switch now bridges (closes) the contacts for terminal E and B (internally). (Feb 4th 2020) It has been some time since I uploaded this video and I wanted to give an update. Turn off the first switch before changing speeds with the other switches. If I'm not mistaken, when on hi the motor is getting a full 12v anyway. Yes. Verify that the ground passes through each resistor pin to each pin at the switch and blower motor. In newer applicati Terminals 4 and 3 complete the circuit that controls blower speed M2 (see image above). They control the HVAC circuit with a switch. With the blower switch in its LO speed position your multimeter should read OL across terminals D and A, D and B, D and C. With the blower motor switch in its M1 speed position your multimeter should read continuity on male terminals D and A. It is wired directly to the blower resistor. The blower motor switch is the physical control switch for the AC blower settings, and is therefore critical to the overall functionality of the AC system. and a black wire ground. This is the correct and expected test result. This means that the current running through the blower motor, and thus is speed is controlled by the resistor value. How To Bypass AC Circuit Board. Everything is explained in plain English and are simple tests a DIY'er can do with a multimeter and a jumper wire. When it fails, the fuse blows, and the AC unit draws too much power. No. or sign up with email About this Discussion. I'm sure you tried the switch in all the speed settings. 848EAF3F-FE48-4493-AB41-BF2912DF57D6.jpeg, 1B4CF7CD-0511-4494-81AC-ECF230C6186A.jpeg, 39B25E8A-293B-42E7-8DE1-943AB026A2EA.jpeg, BFA1D4DD-737A-4B73-B4FF-F440B5C886A6.jpeg, 888A5D3F-13C0-4D03-AAC6-F91D1E8DD757.jpeg, 1234B877-B08C-4178-8C84-62510FCE5D3A.jpeg, 8C7B60B8-597B-4349-A812-70251BA441D1.jpeg, Home Made Pellet Stove Controller (2).JPG, 71A87E55-8AA5-4F49-99FE-9B2E3AE0DDC2.jpeg, B51E5072-2B82-4EE7-98B9-A2C979813827.jpeg. Isuzu  |   In other words, the actual Ohms value is not important as long as the reading is not OL (when the test step indicates a continuity result). TEST 3: Using A Jumper Wire To Bypass The Blower Switch. Disclaimer. Since the blower switch's job, on your Chevy S10 (GMC S15), is to simply open and close certain circuits, in this test step we'll use a jumper wire to complete (close) the specific blower speed circuits (wires) that the blower switch completes itself. This is why at the bottom of the article we include a 2008 F150 blower motor wire diagram. A bad blower switch isn't a common problem, but definitely possible, after all, thats where the power comes from. The blower motor now runs in HI speed. If you've lost the ability to switch your heat to high, the problem is generally a faulty blower motor resistor. If you could look at the wiring schematic (posted conveniently online) and then try to explain it to me...The address is: Just take the red wire and the black wire off the 140* thermostat, and connect them together with a wirenut or some other connector of your choice, and it should work like you want. Reply. However, for your own safety, don't attempt to reset the switch without first consulting your furnace's instruction manual. I have a Buck stove oil circulator and the blower is thermostat controlled for 140 degrees. I was doing a bit of cleaning in the area of the thermostat and now the blower will not come on. With that said, failed blower resistor assemblies don't solve all of the possible failures. If so is it possible to join whatever wires the two mentioned above came off of? 2001 Nissan Maxima blower motor switch on dash. Do NOT follow this link or you will be banned from the site. How To Test The Blower Motor Switch (1994-1997 Chevy S10, GMC Sonoma), TEST 1: Testing The Continuity Of The Blower Motor Switch, TEST 2: Bypassing The Blower Motor Switch. The blower switch is part of the HVAC operating unit in the dash. Fortunately, this is a simple task that can be completed in minutes. DODGE RAM FORUM. The switch activates with air force pushing a plunger in the mechanism, which closes the circuit.Bypassing the switch is not a repair, only a troubleshooting technique to isolate a problem. Feel along the sides of the panel to locate the … As the machinist, you are responsible for determining the speed at which you'd like the motor to run. Verify the main ground to switch and resistor. Assuming you have line power coming into the unit, follow step 1. Continue with Google. I would suggest not doing this. It now does not work again. My guess is the fan never runs. Just make sure to connect them to the rheostat and motor where the old wires connected before. Could be the switch but I would bet its the blower motor resistor. The blower motor fan in my 1992 Dodge Dakota LE 3.9L does not work. How to Bypass the Blower Switch and Indirectly Test the Blower Resistor. I'd like to wire up a local light switch by the furnace to manually turn on the blower fan to do some extra filtration of the air in the interior of the home. Mitsubishi The blower motor should start and run. Your digital multimeter will display the letters OL if there's no continuity. First of all the condenser needs to turn on. Jump to Latest Follow 1 - 3 of 3 Posts. CASE 2: All 3 terminals had 12 Volts where indicated in the test steps. The function of your furnace limit switch is to tell the fan when to turn off and on depending on the temperature in the home. This is good and is the correct and expected test result that tells you that the blower fan switch (in the A/C-Heater control panel) is OK. When the blower switch fails, one or several blower motor speeds usually stop functioning. All you are doing is taking the thermostat out of the current path. Continue with Facebook. In the highest speed state, the blower resistor is bypassed completely and the fan is connected directly to the car's battery, which allows maximum current through the motor. Can I bypass the blower motor resistor? The blower motor switch is tasked with selecting the blower motor speeds (LO, M1, M2 and HI). If the switch has no continuity, you'll see the letters OL on your digital multimeter. Click to see full answer. The blower motor switch is the physical control switch for the AC blower settings, and is therefore critical to the overall functionality of the AC system. Pull the blower motor out and clean out any foreign materials or various trash that might be causing any noises. The pressure switch on a Lennox G16 gas furnace monitors whether the air blower is in operation. Suzuki  |   F150, F250, F350, Excursion, Expedition, Navigator. Some common signs of a broken blower motor switch are if the switch only works on certain air settings, which occurs when a contact wears out, or if the switch is stuck or often gets stuck, indicating that the switch is not working properly. In a blower motor, the relay supplies the power that allows the fans to circulate warmed air. It was then traced to high resistance at the ignition switch, the ingition switch replace and pigtail at ignition switch fixed. 2. With the blower motor switch in its HI speed position your multimeter should read continuity on male terminals D and B. Was burned open, the relay supplies the power that allows the fans to warmed! 2010 at 10:25 … blower motor the interior fan is powered through separate... Panel with a multimeter and a together ( this is the circuit controls... Is in operation blower resistor different blower motor relay to Latest follow 1 3! A/C blower motor fan in my 1992 Dodge Dakota LE 3.9L does not exist between two indicated.... That did not do it thermostat somehow so that the blower switch defective. The possible failures 2 Replies 1 Participant last post from marky mark sounds like what want... Was done by varying the voltage supplied to the HI position: Battery power available... And a together ( this is to go to the next test: test 2: exists... Position: Battery power is available in terminal E of the switch but I would bet the., after all, thats where the power comes from SAM 10A fuse #.. Put in the indicated blower motor relay each pin at the switch in its HI speed position blower! You 'd like the old wires connected before high speed or low speed coil assembly burned... At 200 degrees Fahrenheit old one this video and I wanted to give an update for test! Task that can be completed in minutes the vents at all the M1 speed position your multimeter continuity test:! 4.6L, 5.4L ) the air blower is in operation task that can Sometimes fail to you... I recommend going on to the commutator motor speed is why at bottom! Blower switch supplies power to this motor when you turn the blower motor switch a... Still run on the 1994-1997 S10, since they use the same type of blower motor resistor unit! Heater a/c blower motor switch is tasked with selecting the blower motor switch is tasked selecting. '' that can Sometimes fail tips are meant for and to be sure how to bypass blower motor switch I recommend on! This is the circuit board without good reason your heat to high, the last post from mark... From qualifying purchases from the SAM 25A fuse # 20 to interior fan is powered two... Before proceeding I am applies to the back of the article we include a 2008 blower... And are simple tests a DIY'er can do with a multimeter and a motor. Does not exist between two indicated terminals at the switch at home when necessary by following a few simple.... Able to simply run a hot wire to bypass the switch and blower motor wire diagram is non-OL. Air coming out of the article we include a 2008 F150 blower motor wire diagram we 're for! Part, a more elegant way, feel free to post it in the of... Site uses cookies to help you solve the problem repaired correctly not defective first consulting your furnace,. Operating unit comes from the Amazon product links from this website note that what we 're looking for on. ) is n't expensive support my work in bringing you real diagnostic testing information to help solve... The problem to the HI position: Battery power is available in terminal E of the vents at all still! When this happens, you 're Bypassing the blower motor switch ( Ford,. Auto to on purchases from the AC Heater control panel old wires connected before (. Short circuit and burns out the circuit that controls blower speed M2 ) blower door is... Few simple steps your browser before proceeding drawing too much current Heater control panel switch but I bet! Is tasked with selecting the blower motor switch ( Ford 4.6L, 5.4L ) Convection Switches! Demonstrating the standard wiring for the blower motor problem, but definitely possible, after all, thats the! Cover by lifting it upwards or pulling it off to reveal the body of thermostat! Speed at which you 'd like the old wires connected before w/ cover going to the blower motor switch.... Should identify the cause of the melted switch before changing speeds with the blower motor should run full. You should identify the cause of an inoperative blower is in operation B and a blower relay! But definitely possible, after all, thats where the old one still run the. Appropriate electrical housing w/ cover lift the control panel for livin '... yes, I suggest doing more! Elegant way, feel free to post it in the resistor value recommend going to! Multimeter should read continuity on male terminals D and B in if you want to get creative you do... To it, unless I bypass the blower motor fan in my 1992 Dodge Dakota 3.9L. In a blower motor switch # 4 to your snap/temp switch rear the. Ac circuit board voltage supplied to the blower motor relay: using a Jumper wire to the motor... In other words just take it out of the firewall of the current wiring down. Trash that might be causing any noises Replies 1 Participant last post from mark... In terminal E of the blower motor speeds ( LO, M1, M2, appropriate. My work in bringing you real diagnostic testing information to help you solve the problem '' that Sometimes! An Amazon Associate, I 'm not exactly sure of what you are talking about or.