I switched my function selector last night in my 97 850 from defrost to middle flow and I heard an audible click. The Blower now seems to be stuck on. If I shut down the vehicle the blower ceases and when i crank back up and have the blower on 0 it is not engaged and can go up to 1 2 3 and back down to 0 but if it is raised to 4 it will stay blowing that strong until you shut down the vehicle. This problem as stupid as it may seem is driving me up a wall. Can anyone shed some light on the subject before I start pulling apart the dash.

 

Also the light for the air circulation switch is always on weather depressed or not. Anyones help would be greatly appreciated, I dont want to get new control modules if not needed.

 

Sounds like it might be the blower resistor.

 

Thanks for the reply Tech. Ive looked into your suggestion a little bit and it seems that when the resistor goes its because of a faulty motor, and it also seems that when the resistor goes 1-3 dont work and only the 4 setting will. Do you think this could still be the case for me (1-3 work as does 4 yet once on 4 it stays stuck on 4 power flow until the vehicle is turned off) at first I thought it would be simply the 1-4 fan blower control module. I will get into sometime soon to test the thermal fuse/resistor. Do you know of any way to test the control modules for faults? Thanks again volvogearheads.

 

The MCC controller hardly ever goes bad. I think I have only ever seen 1 go bad. I would say the resistor is bad.

 

thanks again tech Ill take your suggestion and check out the resistor and its thermal fuse before anything else.

 

any suggestions on what i can do if i have stripped the plastic gears in the mcc temp controls and in the dials, im sure I could get ahold of the dials what about the plastic gears that control the arms to pull the wires? At this point im really upset but I have calmed down and would like to remove the unit to fix it. yet i cant even figure out a way to make enough room to do that.

 

I would try to source a used one from a junk yard.
Do you have the front section off yet?
Usually once you have the 4 screws out you can work it down into the radio hole.

 

That radio hole advice is stellar - to bad I figured that out myself after hours of trying to pull the retainer clips off the wires from the mcc hole(at night with a flash light!)because Im stubborn. Boy are those retainers tough when you have no room, lol. Anyways, Finally got the cables detached and I have a fully functional ac system on wires! Still have the 4 setting sticking because I have not located the resistor to test the fuse yet. I did find a resource for mcc controllers online on EbayMotors for 90buh. Ive had no luck findin an 850 in a yard in south florida. In the process ive taken off the top dash and passenger srs. And plan on repairing the cracked old panel, I was thinking plastic superglue on the cracks around the radio, mcc, etc and plastic epoxy behind bad cracks and where screw drives are busted. I was then going to finish the repaired plastic with a highperformance vinyl (like for graphics) to cover the hairlines. for the cracks in the plastic part of the dash under the vinyl i was going to see how a little epoxy, sanded and backed with heavyduty cloth duct would do. Any interior repair tips would be appreciated.

 

2001 S40; fan speed is all over the place, no matter which manual setting you use. Is it the fan motor or climate control thing?
I have heard that the resistor goes bad on the motor and you can just re-solder a new one on.