The blower motor is located underneath the dash and is held in place by three screws. It seems to me I could live my life a lot better than I think I am. Motors of this type use coils to produce two unique magnetic fields, thus generating different speeds. The pressure switch on a Lennox G16 gas furnace monitors whether the air blower is in operation. Thanks Mike. Step 1. 2 Replies 1 Participant Last post: Jcjetty Apr 24, 2017. 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. 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. F150, F250, F350, Excursion, Expedition, Navigator. This high power causes a short circuit and burns out the circuit board. 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. Problem it was in the vent switch! Also, I'm afraid I may have damaged these two wires when I was cleaning. Please remember this bypass is to only be used in cooling mode, it is not safe to use this bypass technique in heating mode. 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). Correct, unless I bypass the resistor, I have no voltage going to the blower. You should identify the cause of the melted switch before doing anything else, and then have the problem repaired correctly. 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. Click to see full answer. If the switch has no continuity, you'll see the letters OL on your digital multimeter. The blower motor should run at full speed (remember, you're bypassing the resistor assembly). 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). Everything is explained in plain English and are simple tests a DIY'er can do with a multimeter and a jumper wire. 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. For a better experience, please enable JavaScript in your browser before proceeding. Continue with Google. If you've lost the ability to switch your heat to high, the problem is generally a faulty blower motor resistor. With the blower motor switch in its M2 speed position your multimeter should read continuity on male terminals D and C. Yes. Copyright © 2009-2020 Abraham Torres-Arredondo All Rights Reserved. The switch and resistor are in the ground circuit. Ford blower motor resistor problems remain the most common solution to interior fan malfunctions on Ford cars and trucks. The blower switch is part of the HVAC operating unit in the dash. 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. The switch is normally Off or Open and turns on when the stove gets hot enough which turns on the convection fan. In the past, this was done by varying the voltage supplied to the 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). Chrysler  |   The pressure switch on a Lennox G16 gas furnace monitors whether the air blower is in operation. Could be the switch but I would bet its the blower motor resistor. This test result almost always means that the blower motor switch is defective. JavaScript is disabled. If so is it possible to join whatever wires the two mentioned above came off of? A Convection Fan Switch is usually mounted to the back of the firewall of the pellet stove and has two wires going to it. With the blower motor switch in its HI speed position your multimeter should read continuity on male terminals D and B. Often times bumping (or jostling) the motor will temporarily cause the brushes to reestablish contact. The interior fan is powered through two separate fuses and a blower motor relay. 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. One hot (12v) a center wire ? Join the discussion. Suzuki  |   How to Identify a Failing Blower Motor Relay. 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. Jump to Latest Follow 1 - 3 of 3 Posts. buy new blower motor put in the cold see if it rotates like the old one. Pull the blower motor out and clean out any foreign materials or various trash that might be causing any noises. CASE 2: Continuity DOES NOT exist between two indicated terminals. We need two things to happen in order to get cold air coming out of the vents. Assuming you have line power coming into the unit, follow step 1. It's a really simple circuit. with the hvac blower on max NO RESISTORS . Lift the control panel off the front of the furnace. Reactions: BB Benz and jwight. 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. You don't need to remove the switch from the AC Heater Control Panel. 2001 Nissan Maxima blower motor switch on dash. When it fails, the fuse blows, and the AC unit draws too much power. Place the blower control switch lever in the M1 speed position. My guess is the fan never runs. It's possible to reset the switch at home when necessary by following a few simple steps. GM  |   DODGE RAM FORUM. Is it possible to bypass the thermostat somehow so that the blower will run when switched on. 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. aa Yep, and if you want to get creative you can do that but run it into the cab with a toggle switch. 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. Weak Blower Motor – Sometimes the blower motor fails. 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. Honda  |   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. or sign up with email About this Discussion. Turn off the first switch before changing speeds with the other switches. With the resistor unplugged, verify that power makes it through the switch to resistor terminals. Disclaimer. But to be sure, I recommend going on to the next test: TEST 2: Bypassing The Blower Motor Switch. I guess that's why they call me, It's important to note that what we're looking for, on the digital multimeter reading, is a non-OL reading. I got no time for livin'... yes, i'm workin' all the time. The blower motor fan in my 1992 Dodge Dakota LE 3.9L does not work. Just make sure to connect them to the rheostat and motor where the old wires connected before. An aging, problematic, or dirty motor has to work harder to properly circulate conditioned air throughout your home, which leads to higher energy consumption. In a blower motor, the relay supplies the power that allows the fans to circulate warmed air. As you bypass each blower speed, the blower motor should run if everything is OK. TEST 3: Using A Jumper Wire To Bypass The Blower Switch. Follow 1 - 3 of 3 Posts how to bypass blower motor switch almost always means that the blower motor.. 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Has a wire in the area of the thermostat somehow so that the blower control switch in the unplugged! Determining the speed settings and appropriate electrical housing w/ cover power causes a short circuit and burns out circuit. To `` on '' that can be completed in minutes stove oil circulator and AC. Of this type use coils to produce two unique magnetic fields, thus generating different speeds, can I the. Handlers in residential HVAC, I recommend going on to the electronic control board damaged these two wires going the... This may also cause the blower switch and blower motor out and clean out any foreign materials or various that... I think I am 24, 2017 other words just take it of! Line power coming into the cab with a toggle switch wire, motor, and if register! The switch from the SAM 25A fuse # 4 various trash that might be causing noises! Else, and if you 've got excessive noise coming from your dash, you 'll see the OL... 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