Blower Fan Problem

[Smokie]

Just came back from a drive with the wife today, during the drive I had the A/C on, blower in a very slow speed setting, Suddenly the fan started blowing in high speed and there was nothing I could do to slow it down, including turning OFF the A/C. The only thing that would stop the fan was turning off the car. Compressor on/off and all other functions such as Floor, Defrost and such do work. Anyway I got out and unplugged the fan. I think the control unit is bad or fan relay stuck in close position. Any opinions or thoughts would be appreciated. Thanks.

[jgc61sr2002]

Definitely an electrical problem. Possibly in the steering wheel if you can't lower the fan speed from the dash controls. Looks like a trip to the dealer. Good luck. Keep us posted.:(

[carfixer]

Have seen the same problem several times, mostly in Town Cars. Our cars have the same system though. It is caused by the blower motor speed controller module. It is in the evaporator housing under the hood behind the right cylinder head. Dealer visit for sure. Good luck.
What part of FL?

[Smokie]

carfixer Thanks for the heads up. I'm taking the car to the repair shop tomorrow. I'll post the results.

PS: Tampa.

[Smokie]

carfixer Had the car repaired today and your diagnosis was right on the money: blower speed controller module. Working fine now and learned how to run a diagnostic on the control unit No codes came up on the MM.-- however I ran the test on my 95' Vic and although I am having no problems at all with my A/C it spit out 2 codes: 115 & 125, go figure ???:confused:

[Murader03]

Smokie......no fair keeping this diagnostic to yourself. You must tell us how to run this .......

[Smokie]

Murader03 I don't mind sharing :)

Car is off, A/C unit is turned off, turn ignition to on position.
Press OFF & FLOOR buttons at same time, release and press AUTOMATIC button. It will start a display of slashes moving in a circular motion and you may hear valves being activated, takes about 30 seconds and then if all is well it will illuminate the complete display. That would be good, if numbers come up, those are the codes to indicate a problem, I don't know the codes myself. :coolman:

[carfixer]

The codes for the EATC system in the MM are as follows:
024, 025 Blend door short or failure
031 In-car temperature sensor open circuit
030 In-car temperature sensor short to ground
041, 043 Ambient temperature sensor open circuit
040, 042 Ambient temperature sensor short to ground
053, 051 A/C solar radiation sensor open circuit
050, 052 Solar radiation sensor circuit short to ground

Smoke, glad it worked out.

[Smokie]

carfixer Thanks for the codes, valuable info. :D