HVAC Blower Problem

[phils97bonn]

97 SE, Climate Control System (ECC: Electronic Climate Control)

She won't blow. I've asked nicely and nuthin'...no blow.
This unit has occasionally had this problem for a short period but it has always fixed itself. 2 days ago It acted up again and the blower quit. I noticed voltage lower than normal so I cleaned and tightened the battery connections. The blower has not worked since. Anyone have any ideas to fix this problem? Do I have to simply replace the entire HVAC control unit in the dashboard?

Thanks for any suggestions.

Phil

[willwren]

It's very likely the blower control module mounted under the maxifuse relay center and above the evap core (on the evap cover). This is a fairly common problem with age. It also can be the fan, and you can do a bypass to determine if it is.

Help with blower module access:
http://www.pontiacbonnevilleclub.com/fo ... =45&t=2432

More information:

Just a few BCM P/N's that have been verified. These are for ECC.

1997: 52470337
1993: 16173860 (replaced with 12368389, works fine)
1992: 12368389

But I suggest getting one from an identical year if possible, from the wrecker. Good troubleshooting part, and if it doesn't help, you have a spare for later. There is a way to bypass the BCM and force fans full, but I don't recall which pin/wire off the top of my head. Someone else will chime in shortly.

[phils97bonn]

Blower motor - Not. I hooked up 12 volts to it and she hums.

Thanks Willwren. I'll check out the BCM.
Took me forever to find it. I shoulda clicked on the above link which showed exactly how to access it. Oh well, I got it out now. Well now on to find a replacement BCM.

[phils97bonn]

HVAC Blower Problem Fixed

Here was the orig. problem: My HVAC blower was blowing intermittently lately. Blower motor was OK so I replaced the BCM as Willren suggested. This is basically a power transistor on a large finned alum. heatsink.

So I checked out a couple places to buy this part.

GMPartsDirect dot com : No. They said not in stock, special order item, may not return, no ship date, no one there to call and answer any questions, slow email reponse, etc., forget this place I said to myself. (I admit their prices are slightly lower than most online sources I have found).

GMPartsDepartment dot com (Hubacher Auto, Sacramento): Yes. Close to same price ($118.66 + 14 shipping, $4 more), much faster response, yes, you can call them. They've gotten my business twice recently. Good outfit.

[ktownSSEiguy]

Had the same problem in my 95 summer before last. 99.9% sure it's the control module as willwren said.
The sad part is, this is a $25.00 integrated circuit but there is no way to determine the pin-out and all pins are not used. $120.00 is about what I paid to replace mine. If I had known what the problem was, and where the part was,I could have rebuilt mine for about $30.00.
Kept my old one, traced and crossed the IC part number and it's a commercial, readily-availabe component. Made me sick. Gotta do what ya gotta do.
First GM i've ever owned-still learning.
P.S.- From a former Electronic Technician/Engineer who specialized in DC, Analog and Custom Interconnect. 35+ years.
My 1965 Mustang was the last car I had I could work on.
Got a shop manual for my Bonnie on the way.

[93RedSled-SSE]

If you can find one of those "u-pullit" yards it is worth the search. I paid $5 ea. for a couple of them this summer (mine would overheat and lock on, even with key OFF). These are either fully good or fully bad, since it is just a sooped up transistor. And they come with a 30-day at U-Pullit (here).

[Yoshicoby]

I pulled two or three at a junkyard. Put the first one on and it works fine. You interested in the others?

[dave1]

yoshi---- I'll take BCM one if you still have any

610-608-4945 --Dave

[Yoshicoby]

Crap. I'm Sorry. I can't find them, so I must have thrown them away. I'm sorry I got your hopes up and now can't help. I really hope you can get 'er fixed. Next time I go to Pick N Pull, I'll pull a couple for you.

[dave1]

well i did find one but would love to have a backup if poss. what would you want for it? thx

[Yoshicoby]

Oh, I'd just have you pay for postage and whatever the junkyard charges me. I'd feel bad chargin you more for the part. I don't mind helping a person out. I can't remember how much they cost, but very little I'm sure.

[Bugsi]

The sad part is, this is a $25.00 integrated circuit. . .If I had known what the problem was, and where the part was, I could have rebuilt mine for about $30.00.

Any idea exactly just what the IC is? I'll rebuild them for people if we need to.

[93RedSled-SSE]

The sad part is, this is a $25.00 integrated circuit. . .If I had known what the problem was, and where the part was, I could have rebuilt mine for about $30.00.

Any idea exactly just what the IC is? I'll rebuild them for people if we need to.

It's not even that fancy; just a 3-legged animal on a heat sink, similar to those in a home dimmer switch, except for DC.... looks like the old SCRs. I think I still have one (good or bad), if nobody else jumps in, will try to check tonight.

[Yoshicoby]

I found two BCMs in a box in my basement. (blower control module). Also have three BCMs (body control modules).

[dave1]

tell me what you want incl s&h
Dave 610-608-4945