OT-blower quit

tomturkey · Dec 27, 2014

I know some of you have older vehicles. I need some help. I keep a 91 Ford Tempo around for a back-up vehicle should one of ours or the kids need to go to the shop. The heater/ac blower quit on me. Initially figured the blower motor, further diagnosis determined I am not getting any power to the bloer motor resistor. I have power at the fuse. Wiring must go from fuse block to dashboard controls then to blower resistor then back up to dashbord hi-med-lo switch then to motor side of resistor to feed blower motor. Hi-med-lo switch is accessable but other controls cant be accessed. I have a multi vehicle Chilton manuel that just does not get into this wiring. Can anyone offer some help advice. Sorry for the long post. I need to get this out of the shop to bring in my DC lp. gobble

casecollectorsc · Dec 27, 2014

Those year Fords, IMO, all have trouble with the heater blower switch. Got a Ford semi tractor and have put a few in it. Parts guys say it is the same switch for cars, pickups, or big trucks of that age. Course when over the road in the semi it never got turned off from Sunday to Friday in the winter sometimes. I'd make sure the blower switch is good.

tomturkey · Dec 27, 2014

Thanks, Its gonna be a bearcat getting that thing out. gobble

Lpakiz Larry · Dec 27, 2014

I had a 84 ford ranger. The heater switch was not very robust, so I repaired it several times. If I remember correctly, the blower motor has 12 volts to it whenever the key was on. The heater switch provided several paths to ground. The several paths I speak of were routed thru the ceramic resister, which was inside the blower housing, so cool air could flow across it. Unplug your blower and see if 12 volts and a ground make it work. If so, the motor is good. Next, try grounding it just downstream of the ceramic/porcelin resister. The slower speeds make the resister glow the brightest. Also, if I remember right, when the blower was on high, the resister had no function. Seems like the blower switch had several wires going in (from the resister) and one going out, which was right to a good ground. That way, the blower switch provided varying amounts of ground for the blower motor.
This is just backwards from the way most circuits are designed.

tomturkey · Dec 27, 2014

This grounding systen is beyond me!!!! But, with 5 wires coming into the resistor on one side and two going out to the blower motor, something should be hot coming in when the ign is on. I have nothing. Yes I did run the blower with a hot and a ground so it is ok. Must be the multi-function pushbutton dash switching. One purplexing issue, when ign is on and I push any of the buttons the radiator fan starts. Soooo something is working while something else isnot. I really dislike vehicle electrical problems!!!gobble

ShakerPrairie · Dec 27, 2014

Tom if I remember correctly my 86 Tempo has one big electrical plug on the back of the fan switch.
Your newer Tempo has a different controls layout than mine, but on an 86 you can get the fan switch out thru the front of the dash if you take enough stuff apart first.
Figuring out which wire is which and testing it could be a bear but it could be done if you can just get access to it.
About 10 years ago I had to drop the steering column then take dash loose and lay it in the seat just to change a heater core in the Tempo.
It was easier than I thought it'd be but it was still an all day job.

tomturkey · Dec 27, 2014

Thanks for the input it is appreciated. Yes I've worked on it several hours already and have not gotten it to clear the dash enough to do anything. Between the cable to the heat/cool damper, the three vaccum lines and the electrical connections, theres not much play. I may have to take out the dash yet. Ofcourse I have to anticipate when I do get access it wont be the push button controls but something else. gobble

OT-blower quit

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