My stock 97's blower motor runs full blast with the engine turned off. I wired a switch into the blower motor's ground wire for a temp. fix. I've heard that replacing the blower control module will fix the problem. Anyone know if this is true or have any expreience with this? recommendations?

 

replace the power module[blower resistor pack]

 

There was a technical bulletin out which installed a kit that made the fan blower stay on to reduce moisture and smell in the air conditioner. If you didn't have your car from new, it may have been installed.

 

Where is the best place to pick one up? Dealer parts counter?

 

Had that happen to my Buick, More than likely is the module.

Module usually located under dash, might be best to take it to a GM dealer to get the part and installed.

 

I had this happen to my 97 last year. BCM has to be replaced. $$$$
Part alone is about $1100. I did a temporary fix with an in line cutoff switch, but only worked for awhile and then you couldn't control the fan speed, would only blow full force. I have a copy of the service bulletin handy at my office. Common problem with the 97 vette and Buick Century.

 

Here is a link to a parts store I found on the internet. Is this the part I need to replace?

http://www.artscorvetteparts.com/par...d-95d38ca04379



Click here: Art's Corvette Parts

 

I got a price quote from GM for a blower control module: GM Part number: 52479971 The price was 164.32. That is far from $1100. Are we talking about the same part???

 

Very possible. These are add-on units and carry a GM part#. I can't recall the programmed "run" time on that thing, but try letting the blower motor run a few minutes and see if it shuts off by itself. If it does, you found your answer. HTH

BTW, the GM# 52479971 is $82.00 and change through GM Parts Direct. So if it turns out to be what you're looking for, you'll have a ballpark on the price. I'm sure it's even less expensive thru Fichtner Chev or Fred Beans.

 

Problem is actually the in the software of the HVAC control assembly.

BLOWER MOTOR - RUN ON WHEN IGNITION IS OFF #83-11-10 - (Jan 27,1998)
SUBJECT: Blower motor run-on when ignition is off (replace control assembly)
Models: 1997 Buick Century, Regal 1997 Chevrolet Corvette

Condition:
SOME VEHICLES EQUIPPED WITH AUTOMATIC TEMPERATURE CONTROL (RPO CJ2) MAY EXPERIENCE AN HVAC BLOWER MOTOR RUN ON CONDITION AFTER IGNITION IS TURNED OFF. THIS CONDITION CAN OCCUR APPROXIMATELY ONCE EVERY 1400 IGNITION CYCLES. CYCLING THE IGNITION SWITCH BACK TO THE "ON" POSITION WILL STOP THE BLOWER FROM RUNNING.

Correction: Replace the control assembly part number 09356081 Control, Assembly Heater+A/C (97 Corvette)

Cost ~ 1100.00

 

Aggie Doc -

You helped me out with this situation in the past, but I put it off and found another post, and spoke with another Tech that happens to have a 1997 model that had the same problem, and replacing the cheaper blower motor control module fixed the problem.

http://forums.corvetteforum.com/showthread.php?t=320529

I'm going to try it first, rather than replace the BCM and hope for the best. The part no. I'm going to replace is the 52479971 mentioned already. When I checked the connector that slides into the control module and read the voltages, as MarkSee5 did (see post above), I found the same thing, no power coming from the tan wire. It would appear to me that there's some sort of short in the blower control module since it's not getting a signal from the BCM to turn on. So, I'll let everyone know how it turns out. I'm gonna try to get one from vette2vette.com since he quoted me $50 for a used one - shipped. I'll let everyone know how it turns out.

 

I just had mine replaced last week. It's only $38.65 brand new from the dealership in West Palm Beach. Labor is a different story. Apparently they had allot of problems and changed the module. The new ones look different. The mechanic showed me where mine was burnt. Oh yeah. They usually go bad when they come in contact with water or antifreeze. Make sure you don't have a leak in your heater core or a stopped up a/c drain.

 

O.K., there's a lot of confusion on this subject and I won't spend any more time trying to figure it out. This is what I know. There are two types of AC control offered in the Corvette for 1997 (and other years, but I'm not going to try to diferentiate), one has the RPO # CJ2 and refers to the automatic temperature control - you set the temp. on the control screen and the fan speed is automatically adjusted to maintain that temperature as a result (temp from AC or heat is also controlled, but by something else?).

O.K., I think the resistor noted by 'shakainc' is for those AC units without automatic temp control and is part number 89018643 (which is a new part number according to GM Parts Direct).

The blower motor control module is for the RPO CJ2 units like mine. Part number 52479971, and is more expensive because it employs a variable frequency drive, of sorts, to control the blower motor speed. Then there's the software issue in the CJ2 HVAC Control Software, detailed in TSB# 83-11-10. It just comes up described as "Control" on GM Parts Direct and is quite expensive; I don't know WTF it is. It's more expensive than the PCM or the BCM and I don't know where it's located. (EDIT: AHA!!! Just figured it out using the link above to Art's Corvette Parts...the part listed in the TSB is the control head in the dash, and there are people all over that can repair those things a lot cheaper than replacing with a new one.)

All I know is that replacing the Blower Control Module (part no. 52479971) fixed my problem.

The old one I took out was shiny silver and exposed to the airstream for cooling. The new one has cooling fins. Hmmmmm, think they figured out the original design was bad and allowed the unit to overheat and burn out???? This is apparently only for the early model Vettes since the used one I got is from a 2001 model. All new replacements have the fins according to pictures I've seen on the internet. Hope this helps those people out that run into this in the future. As for the TSB?!?! If anyone can help explain that one to me, I'm all ears. I'm just glad I didn't order that part and waste in excess of $550!!!!!

 

hey so I know this thread is like a millennia old but I recently got a 2003 Z06 with that CJ2 auto climate system (I think all Z06s got that after like 2002) and I’m noticing the mildew smell from the A/C does that mean I don’t have that heater kit add on? Or that I have it and it went bad? Also were they even Installed on Z06s cause I heard that apparently that was a dealer installed thing and also since C5Zs have no cabin air filter either I’m thinking they may not have it. Nonetheless I’m kinda confused and I’m wondering how I can go about installing that unit if I’m missing it or whatever I need to do. Any help is amazingly appreciated. - Joey