As soon as I start the car the blower fires up and is loud enough to hear inside and out of the car. Seems to be a relay or module of some sort, however this is a new one on me? The stealership told me to replace the entire HVAC system, yeah right, those guys just refuse to tell the truth! Any and all suggestions would be greatly appreciated.

 

I "think" there is a blower motor control relay that sits somewhere behind it. I have your same problem in reverse, mine wont cut on. i pulled my blower out and it works fine when connected to the battery.

 

Yep, I am plagued with this same "reverse" problem. For no apparent reason, the blower completely stopped working a few days ago. Checked for codes and none come up at all.

I too loathe the stealerships. Sethmo99, you might want to check for codes if you have not done so already.

 

sounds like your relay is stuck open. Replace the relay

 

I have turned off my car, removed the key and got out before and had the blower stuck wide open. It's happened twice in the ~1 year i've owned it. Any ideas what thats about? Would it be similar to this?


Dan

 

Blower motor control module. I bought one used somewhere. Search my handle for posts... I think I went through this a year ago. The module bolts into the ductwork under the dash, passenger compartment... real PITA to get to. The old ones just have a metal plate exposed to the air stream for cooling. The new ones actually have cooling fins. I went through all the advice and felt like this control module couldn't be the problem... looked at the HVAC head control unit in the dash, the other computers, but finally found some posts that made some sense, did some tests (I think).... anyway, if the blower mysteriously stays on after turning the car off... starts by itself in the garage and runs the battery down, or you can't control the speed anymore, I'd bet money that it's the BMCM... not terribly expensive and relatively easy to get to if you don't mind laying on your back like a contortionist shoving your hands into places that are too small.

 

any of you guys have the GM part #? or a picture of said module?

 

-update- I just pulled that part out. be forewarned.. they werent kidding when they said it was a PITA to get out. the two first bolts are ok. but the last one that is hidden behind it and sandwiched between the part itself and some insulation, youll need a snake-like tool and some insane patience to get it out. part number is 52479971

 

I have a 97 that is at the dealer waiting to get repaired...motor is off blower keeps running. I have searched the web for the part for a 97 is double that of a 98-99...is it the same part? Can a 98 part replace a 97? Part # for a 97 is 9356081. The dealer states the part is $1400 I have found it on the web for as little as $400 but still looking. The price for this part for a 98 is about $200. Any help would be great....

 

I have been following these threads with great interest as I have the reverse problem.

I noticed here there has been reference made to "Blower Motor Control Module". From my look in the service manual, I don't see this terminology but I do see it refer to "blower motor control circuit" and "blower motor resistor assembly". Here is a picture that supposedly shows the blower motor resistor assembly removed,



Where is the blower motor control circuit/module in relation to the blower motor resistor assembly? Or I am just confused and the blower motor control circuit/module and the blower motor resistor assembly are the same thing?

Thanks,
Matt

 

Here is a picture of the part I am referring to. I dealer said this is what has gone bad and that Chevy has some posted notes as of 2002 that this was a problem. The 97 part and the 98 part are identical but are they interchangeable?

http://cgi.ebay.com/ebaymotors/1997-...QQcmdZViewItem

 

Toybox- the part you are referring to will not fix your problem, also, that part can be had for about $100 refurbished, I know, I bought one and it works fantastic, ill find the link and post it.

Z06ster, the BMCM (blower motor control module) is located behind the blower motor itself. remove the blower motor, and when you disconnect it from its plug, you will see the BMCM that the wires come out of. while you have your blower motor out, you can use some jumper wires (little wires with the alligator teeth clamps on either side) to connect your blower motor directly to your battery. if it cuts on, my guess is the BMCM is gone bad. Ive found BMCM's for about $85-$120 on the internet and I listed the part number in one of my above posts. the part number you probably have on yours is different because the part number i listed was for the upgraded or superceeded part WITH cooling fins. HTH,

-TIKI-

***edit*** Toybox, if your lights are dim on your HVAC control and you want to replace it, i HIGHLY reccomend this person. http://cgi.ebay.com/REBUILT-97-CORVE...QQcmdZViewItem however, if you dont have a problem with the unit itself, id ask the dealership to test that BMCM first.

 

Work # 502-315-6169 Cell # 785-375-7731

 

N/m

 

did anyone get their problem fixed?

 

The picture provided by zo6ster is the component I was referring to as the "blower motor control module." It's actually one of two different parts, depending on which HVAC system you have. For the auto temp HVAC, it's the BMCM; for the non-auto temp, it's a resistor.

See the copy and pasted post below the >>>>> for an explanation.

There was a TSB to replace the expensive head unit that toy11box has a picture link to.... the stealership should troubleshoot before replacing it, though, and there is a simple fix.... again, go to the links that show up with a search described below, and you'll find all the info (and more) that you need.

I did a search using my name and the word "blower" to find this in the archives. Hopefully this will explain everything and eliminate some of the confusion and save you guys some money. Warning; there is a lot of confusion on this issue and is reflected in the thread I copied and pasted from, but if you want to look at the entire thread (it will appear as deja vu to you all) it is located here:

http://forums.corvetteforum.com/show....php?t=1349500

toy11box, have the stealership do the following, as described by another forum member. This is what I had to do to determine which component had fried (credit goes to MarkSee5):

"I then pulled the connector going to the blower motor control module. Using a voltmeter, I saw that pin C had no voltage, and pin B had +12. The manual says to replace the blower motor control module next. gmpartsdirect.com has it for $70."

Last, if this isn't enough information, go the the search, select 'archives' and 'c5tech', put topcat in as forum member name (or whatever that blank says) and blower as the key word and look at the different threads that come up, but be ready for LOTS of confusion. What I've pasted below should help you out and if you have any questions, don't hesitate to PM me!!! Really, I don't mind.... and if I don't have the answer, I'll tell you so.

Good luck, guys, and I hope that it's this pictured item for all you guys since it's relatively inexpensive compared to the other components. BTW, got my used from a supporting vendor here on the forum (I don't know if they're still supporting vendors, so my apologies if they aren't).

http://www.vette2vette.com/
They specialize in C4 - C5 used parts. Can call or query their web site.

:Cheers:

- TopCat

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>

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 on the back side 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???? (Note: an air intake filter would be a good idea to keep the fins from accumulating dust, which will insulate and keep the heat in the module.... resulting in premature failure... again!). The shiny, non-fin design 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!!!!!

 

Hmm, perhaps I was mis-informed, but I was told that the TSB for the headunit was really because of the resistors that die out and cause the display to go to hell. As for my problem, im going to re-connect the BMCM today and get a voltmeter on it to see what im pulling out of "pin C" Im putting my money on the fact that the BMCM has gone to crap.