Understand Blower Motor Circuits to Better Diagnose Problems (Season 5/E12)

[SexyStang]

Resistors can be repaired....you will usually find cracks in the wiring if you look close, you can re solder them....since each wire path is responsible for 1 individual speed, that's why you often lose 1 or 2 speeds at a time.

[robertleewhitt]

Outstanding, the voltmeter really made me understand >
I’m replacing my resistor on my jeep 2006 liberty > the fan motor does not work on settings one and two, but works on three and four . It kind of works like a rheostat .

[deankay]

My brother-in-law took his Ford Ranger to the dentist and bumped a parking lot curb. His truck started and he came back to our house. Later, it would start as it just cranked. I ask him about hitting anything, he remembered the dentist. The “Inertia” switch was below the glove box, I found it, pushed the button and started right up. Never failed again.
Also, police and Highway patrol had a small paper guide to reset this device if they needed to help or move a vehicle.
ASE Master Tech since 1978-Retired

[betoable]

Very helpful!! I’ve never used blue prints or schematics…
I’m trying to fix blower motor today… just from this video I can tell the problem is the resistor!!

Thanks again!!

[moniquewrites]

What if sometimes the air/heater works but sometimes it doesn’t

[techseth]

My old blower motor use to blow so hard it’d melt the connections. The new one I bought from RockAuto is way less powerful, but I’m no longer replacing a connector every week. I’d say I had a unique problem

[samuelanderson]

Thank you I have 2003 Lincoln town car I have to change my blower motor resistor

[motivationindrive]

Soo what your saying is I should be able retrofit the big 12” style touch screens with climate controls built in into an older 2006 ram 1500

[Fast_Forward_Racing]

My cars blower won’t turn on unless the car is in accessory mode (not cranked) and on high. If I crank the car it won’t work on any setting. I replaced the resistor and blower, but no fix. All fuses are good. The resistor has 4 wires, when in accessory one wire has power but when cranked that wire loses power and another wire has power. If I sent the current over into the other wire then the blower motor will turn on (and will work on all levels) but if I turn the car off it won’t work when I crank the car back up. This has me stumped, any recommendation?

The car is a 2013 BRZ limited (automatic)

[lens]

Question. My blower starts then slowly comes to a stop and shuts off. After some time it will randomly run again then shut down again within seconds. Idea?

[AliGan]

Thanks for the video, but I you guys were explaining a little slower...

[MrDrumHunter]

Hello and thanks for the great info!! I have a problem with my w202 c180 Mercedes 94' (code of the unit: A2028300785). Even if I remove the key from the car, the blower keeps working at maximum speed. Blower motor and resistor are new. I can't find why is this happening please help !!!

[Quintos.]

I got a land rover im working on when i put a test light the blower motor doesnt light up but when i put a multimeter on it the fans wiring harness says its getting 9 volts but the fan blower motor doesnt work but when you bench test it with 12 volts it works fine. The relays are clicking and it has a brand new resistor. I dont get it.

[kevinbui]

After blowing air for about 1 minute, My Mercedes clk430 blower motor stops. And the heater/AC control dash board went blank. Blower motor fuse is good, I replaced the resistor. I assume the fan motor is good, since it blows air when first started. What could be the issue? The Relay?

[jeffwebber]

What if I have 12 volts low to high at the new blower motor purple to ground and it still doesn’t work?
I tested the new blower on the battery and it does work.

[dalewilson]

Does the Blower Motor and Resistor have to match in order to work....?? I put a new blower motor on my 72 Mustang and it works on all speeds, ,,without the car running and a minute or two the glass fuse gets really hot and the switch gets warm...12 volt blower

[arealmaintenanceandrepairl]

Does that also effect the compressor say it senses blower resister is bad and it default to not let compressor run

[williamgrissom]

The blower controls in my 1960's Chrysler cars didn't have a relay for "blower high" position, just routing that thru the switch. Result after a little corrosion was "melted switch". GM and Ford were likely similar. To mitigate that, I added a relay, as shown, so the "Hi" position turns on the relay, bypassing the high current around the switch. In some, the electrical switch was integral with a push-button vacuum switch, which costs ~$100, so melting one was to be avoided. Similarly, I added relay for "ACC" key position to keep that current off the ignition switch. Same issue in my 1985 M-B 300D, where I added a relay so the #8 fuse-holder doesn't melt (guessed it, "cabin blower").

In my 2002 Chrysler T&C w/ Automatic Temperature Control (digital) option, the "resistor" is actually a transistorized board, which I think does Pulse Width Modulation control of the blower motor. Like the resistor pack, it is bolted to the side in the climate box to sit in the air-flow (behind glovebox). When it fails (usually overheated), the blower usually runs on max speed and can't be adjusted (transistors usually fail shorted).

[papanutt]

I'm color blind. I have a 93 Mercury cougar xr7 WITH automatic climate control. I'm having to rewire the auto resistor for the blower motor and the new pigtail has all white wires. Hints to why I'm asking for help. When I got the car someone had cut the old pigtail wires off to try to put an analog resistor on the car but the climate controls in the cabin only work with auto climate resistor. Could anyone tell me which wire goes to which for the pigtail from the wiring harness? Any help would be appreciated. Thanks so much.

[nathanbradforth]

My climate control unit has lost power as it won't turn on however the built in stereo still has power. It is 05 outback. Any recommendations? Thanks