Write-Up: Blower Motor Control Module Replacement

VJD2 wrote:

My car started doing this today. Can't complain since the weather has been abnormally warm.

If you don't mind me asking, how much did the replacement from Ed Morad cost you?

I'm thinking of going that route since there aren't many Riv in the yards around here.

It was $50.00 shipped. It may have gone up since last year. You can find it new for around $100 on Amazon if Ed doesn't have any in stock.

That is reasonable. I'll have to give him a call. Thanks for the info.

I found one on Amazon for $102. Cheapest I've found yet if Ed falls through.

confirmed workin. i used one from a 1995 buick roadmaster. it was the only one i could find in the junkyard that had the same plugs as ours and they let me test it before i bought it. not only did it work but it went back in with no modification to the fins or anything. as the plugs where the same and mine where corroded i soldered the better ones into my harness when i got home. ac is workin again and i got off buyin a 20 part instead of payin out the nose. on a side note bein 6 ft and 280 makes for a bad time trying to get into the blower motor area! lol

jsm wrote:

I recently had the blower motor on my 1997 Riviera stop blowing. I did some research and found out it's often the blower module (which I've had people also call a resistor pack), and that the part was about $220 and impossible to find.

I grabbed one out of a 1995 Riviera at a scrap yard, changed it out, and still no love from the blower. I did some more research and found out some places that list compatibilities show that the part for a 95 is different from a 97. So what I'm trying to decide now is if the two should interchange, or if maybe the one I got from the scrapyard is bad, or if it could be something else entirely. Before it went out, it went on and off intermittently, if that helps. A garage checked it out and said there's just no power going to the blower motor, but finding out more would be $60 for a diagnostic.

Just bought this, and in the past month I've had to replace both front wheel bearing assemblies, the belt and the oil sending unit, so I'm hoping to be able to do this myself without any more high costs. Any help would be appreciated!

Well this just happened to me. Blower motor would need a tap every morning to get it going, so I pulled out the blower motor took it apart and saw that the charcoal pieces were low and one of them was kinda stuck, and the spring was unable to push it out without that tap in the morning. So my dad had some new charcoal pieces from an old vacuum motor lying around that we soldered in to the blower motor assembly. They were a little thinner than the originals but when we hooked it up to a test battery it started right up. So we plugged it into the wiring harness in the car and it went to start but then it stopped and now I haven't been able to get power to it, or the new AC Delco unit I just bought. When we tested the blower plug coming from the car it seems that there is no power there. I checked ALL fuses and found the HVAC CNTRL fuse (10) was fried, replaced it and still no go. So I took out the HVAC module or resistor to see what going on there and found a lot of crud. So I cleaned it up, used some die electric and still cant seem to get the blower going. What do you guys think it is, can you test the module? Got an 8 month old I need to keep warm this winter.

check the plugs. mine was so coroded the tips had broke off in the plug. i had to splice new plugs in because even after gettin it out it would lose connection because of it. then also check the fan just to be on the safe side

Thanks for the suggestion Josh, but I just wanted to confirm that in fact it was the Blower Motor Control Module that was fried. I guess splicing in new the motor brushes from a vacuum was too much for the module. Anyway, replaced the module and I got power to the motor. Thanks for this thread Scott.

hello, I was wondering if theres  way to hard wire with a paperclip or piece of wire to check if its the blower motor or control module. My motor just stopped one day kinda slowed then cut off. thanks !!

MrWood wrote:

hello, I was wondering if theres  way to hard wire with a paperclip or piece of wire to check if its the blower motor or control module. My motor just stopped one day kinda slowed then cut off. thanks !!

I wouldn't go hard-wiring anything regarding the BMCM. I would wire 12 volts via a jump-box or something to the blower motor and see if it works. Keep your fingers away from the cage.....it WILL want to fly

I looked at the plug that connects to the BMCM and it looked corroded on one of the contacts on the plug... problem maybe????

MrWood wrote:

I looked at the plug that connects to the BMCM and it looked corroded on one of the contacts on the plug... problem maybe????

White corroded or green corroded? If it's white, it's just some terminal fretting that can be fixed with some dielectric grease. If it's green, the connector probably needs to be replaced.

Abaddon wrote:

MrWood wrote:

I looked at the plug that connects to the BMCM and it looked corroded on one of the contacts on the plug... problem maybe????

White corroded or green corroded? If it's white, it's just some terminal fretting that can be fixed with some dielectric grease. If it's green, the connector probably needs to be replaced.

well its the red wire on the 2-position plug thats corroded, the contacts on the 4 position seem ok, checked all the fuses (10a on the IP and the 30a under the seat) both fine. no rivieras in the JY for 200 miles of me any idea where i can get a harness or a BMCM....also looking for Driverside window switch and a door handle then shes tip top again cant seem to find this anywhere

or a list of cars to search for with compatible/interchangeable parts please.....

I was in and out of every GM that was made in the mid to late nineties at the local wreckers, and none of the BMCM modules I found were compatible with the Riv. Save yourself some time and look instead for an authorized AC Delco dealer. They have new ones for about $135.

Hello Everyone,

I own a 1996 Buick Riviera with about 102,000 miles and it's been quite loyal over the years.
A few weeks ago, the AC blower and driver side engine fan stopped working. My mechanic has checked all the fuses and relays and all seem to be OK.

I Retired and moved to St Lucia, W.I. a few years ago. With the only Riv. on the Island, experts are few and far between. I am hoping someone assist.

Thanks a million and Happy New Year to you all

Hi,
Often this is caused by the blower control module. Sometimes you can get good used ones from the site "car-part.com"

Hope this helps, and welcome to the site! This place is a fantastic resource for knowledge on your car.

Thanks again. Is there anyway to test the blower control module and does this also affect the driver side engine fan.

Is there air coming out of the passenger vents?  Does air come out of the vents if you manually change the fan speed to a higher setting?  The blower control module controls the blower speed for all of the settings.  Heat, a/c, vent, front defrost. I merged your thread with the blower control module thread to give you more information.

Great idea, and thanks. I did go through the thread and I will try to order the blower module. Will update after installation about 2 weeks. The part takes a while to get here.

I have also manually changed the fan speed but no air comes out of the vents

LaSocier wrote:

Great idea, and thanks. I did go through the thread and I will try to order the blower module. Will update after installation about 2 weeks.  The part takes  a while to get here.

I have also manually changed the fan speed but no air comes out of the vents

So the Blower Motor doesn't work at all? Have you tried manually supplying power to the Blower Motor itself to make sure it still works? You'd have to pull the Blower Motor out of the car to test it. You can use a Jump Box, or some wires with a car battery across the terminals. Hold on tight though....that thing WILL fly away. It's definitely a "backyard" testing method.

No sense in ordering a BMCM if you don't need one.....

We removed the blower motor and manually supplied power to it and it works fine. My control Module has Delco Part number 16173860 with two connectors. One connector has one Red wire, the other has a Brown, Black, and Grey with black stripe. Do you have any idea what the Grey wire is for? The Red has 12 continuous power. The black and Brown goes to the fan.

This is for a '98. I don't have access to '96 anything anymore. I'm pretty sure they're the same. Hopefully it helps....

The Gray Black runs from the blower speed control portion of the Heater/A/C Programmer to the Blower Speed Control input of the Blower Control Module.

We were able to isolate the problem to the Heater and A/C Programmer with the help of the schematics... thanks a million. The mechanic put 12 v at point D14 and the blower came on. Is there a way to test Programmer? Just to double-check.

There is also a problem with the cooling fan and it seems that there is no voltage at pin 30 of Relay number 1. Any idea of what could be causing that fault? And can you direct me to a site where we can get a copy of the cooling fan schematic.

Again thanks for all you help

Alexis

There really isn't a way to test the A/C head, no. All you can check for is power, ground, and outputs respectively. There is a guy on Ebay that rebuilds those units and sells them VERY cheap compared to new. All he asks for is a core.

Cooling Fan Relay #1, Pin 30, gets it's voltage directly from the 60A Cooling Fan fuse in the underhood junction block, and should be hot at all times. That fuse gets it's power right out of the Junction block....direct battery voltage.


Here is the next cell

I have been out for a while on business. Returned today and changed relay #1, now the fans come on, but the ac blower does not. Put 12v to the 10a blower fuse and the blower came on. Any suggestions... also is there a wiring diagram for the Heater and AC Programmer? If yes I would greatly appreciate a copy... and thanks again for all you help.

Alexis