Heater - A/C Fan Control Switch

[Twins03]

All of a sudden, my 1-3 speeds stopped working on my blower. 4 and 5 still work just fine. When I turn the swith to 1-3, the lights turn on as if it works, but nothing blows. Any ideas? Any suggestions? Vehicle is out of warranty and the dealer is awful.

Thanks
Scott

[adamjeeps]

I believe this is your problem. Should be a cheap part but might be a pain to replace yourself. Not sure where it is on the TB.

[04TBEXT]

THE BLOWER MOTOR RESISTOR CAN BE SERVICED SEPARATELY. THIS RESISTOR IS LOCATED IN THE RIGHT SIDE OF THE HEATER CASE FROM INSIDE THE OF THE PASSENGER COMPARTMENT. THIS IS FOR A STANDARD (NON-AUTO) HVAC SYSTEM. TO R&R THE RESISTOR:
REMOVE THE RIGHT SIDE BLACK PLASTIC CLOSE-OUT PANEL UNDERNEATH THE I/P @ THE GLOVE BOX. IT IS HELD IN BY TWO SCREWS @ THE LOWER EDGE OF THE I/P AND HAS A FLAT TAB WHICH FITS INTO A SLOT IN THE FIREWALL. ONCE REMOVED, LOOK ON THE HEATER CASE FOR A RECTANGULAR BLACK PLASTIC PIECE (APPROX. 2" X 5") WHICH IS HELD IN BY TWO SCREWS; (1) EACH OF THE LONG SIDE OF THE RECTANGLE. YOU WILL FIND A FLAT SEVEN PIN CONNECTOR PLUGGED INTO THE RESISTOR. THE RESISTOR ALSO HAS A TWO-WIRE PIGTAIL (WIRES SHOULD BE PURPLE & BLACK) EXITING THE SIDE OF THE RESISTOR OF APPROX. 6". IGNITION MUST BE OFF (I RECOMMEND DISCONNECTING THE BATTERY AS SOME VEHICLE MODULES STAY POWERED UP TO 4-5 HOURS AFTER THE LAST IGNITION SHUT DOWN). THIS IS SPECIFIC OF T/B WITH AUTOMATIC DUAL ZONE CLIMATE CONTROL STYLE HVAC SYSTEMS. DISCONNECT BOTH WIRING PLUGS, R&R THE (2) SCREWS HOLDING THE BLOWER RESISTOR IN AND THEN REVERSE THE PROCEDURE. IF YOU POST THE LAST 8 CHARACTERS OF YOUR VIN, I'LL GIVE YOU THE PART NUMBER.

[mvftw]

04TBEXT, I have Dual Zone, Auto Climate in a '03 LTZ. All the fan speeds don't work. I believe it's the resistor module (I checked the blower fuse). Is it part # 52495874? Also are you saying that I have to disconnect the 2 wires, then unscrew it?

[coastie22]

speed 5 is busted on mine.all other are fine.

[TA Dave]

Thanks to 04TBEXT - I followed your instructions and now my heater fan works great! That's especially important here in Michigan at this time of year.

One noteworthy item - the new resistor had a plastic rectangle on one side that made it impossible to install in original orientation :mad: (we call this mistake-proofing in the industry). When I installed it backwards, the blower motor power wire wouldn't reach the motor. Also, the 7-pin connector would be practically impossible to remove if I ever did this again because the positive lock clip would be facing the firewall, not the interior.

I ended up cutting off this rectangle with a Dremel tool and installed it in the right orientation, and all worked perfectly.

Last note - you need a 7mm (I didn't check for a US equivalent) socket to remove the close-out panel and a 7/32" socket to remove the resistor itself. They are screws, but hex-headed, not phillips.

TA Dave