1997 850 GLT Climate Control Gone Haywire

FullbrT · Post by **FullbrT** » 17 Nov 2014, 17:46

Tell me if you've heard this one before, because I could not find anything like it in the forums.
OK, so the recirc. and A/C lights flash and then go out, but then the fan just keeps blowing full steam and I have no control over it whatsoever. I have flicked all the switches and turned all the knobs and still no effect. I just unplugged the blower motor just to get it to stop. I don't even know where to start looking to find the problem, please help.

Post by **abscate** » 17 Nov 2014, 18:24

If you have manual climate control you probably have a wiring fault in the harness .

If you have electronic climate control, The flashing lights are telling you the Electronic climate control (ECC) control unit is recording a fault. After about 20 seconds of flashing, you may find you can control the vents and fan speed. If it does not stop flashing you probably need a new unit. A pick and pull is the best route

Technically, ECC refers to the type of climate system, but people often use the ECC term to mean the control unit.

FullbrT · Post by **FullbrT** » 17 Nov 2014, 18:39

OK, the thing is that the lights are not flashing. Even after turning the key off and on, disconnecting and reconnecting the battery etc, if the key is on the fan is blowing full speed vent into the cabin. I cannot turn it off nor can I decide from which vents it blows. There are no lights in the climate control panel, the controls do nothing and the fan is going like mad. Is this just a bad ECC unit?

Post by **erikv11** » 17 Nov 2014, 19:20

FullbrT, what you describe is a classic outcome from failure of the blower motor resistor, also called the power stage for the ECC. I don't know how to troubleshoot it other than swapping in a good one, I keep a spare in the garage. This is an expensive part and I wouldn't hesitate to use a junkyard replacement, they don;t go out very often.

Note, usually a failing blower motor is what kills the resistor, so you should probably replace them both.

FullbrT · Post by **FullbrT** » 17 Nov 2014, 19:24

So that would be this part here:
http://www.ipdusa.com/products/7372/115 ... te-control
Right?
I changed out the fan not too long ago but maybe the resistor just now gave out.

Post by **erikv11** » 17 Nov 2014, 19:35

That's the one. There may be cheaper suppliers but yes IPD has been around a long time.

FullbrT · Post by **FullbrT** » 17 Nov 2014, 19:39

OK great, just went out to the garage and pulled the thing out, will get to calling around the local salvage yards in the morning.

Post by **jreed** » 18 Nov 2014, 05:06

I bet you'll find one if you've got old 850's in the junkyards like they do around here (Raleigh NC area). I pulled out an ECC blower controller from an old 850 the last time I was at the junkyard. I think they charged me about $10 for it. I haven't tried it out yet... I just figured it would be prudent to keep one in store just in case the original one on my '97 goes out.