FAQ: HVAC Blower motor only works part time, or stays on

It's called the blower control module.

Lately on my 98 the HVAC fan has been erratic even under manual control. It seems to shut off, slow down then act normal. Any ideas of either maybe the switch or the fan itself. While working there is no abnormal noise from the fan.

Passenger side under dash panel remove and you will see blower motor. Next time it slows down or stops hit with a tool to see if it changes.

1995 Riv wrote:

Passenger side under dash panel remove and you will see blower motor. Next time it slows down or stops hit with a tool to see if it changes.

already tried that.

So far, at autozone I found the blower motor for about $50, and the module for $225!

At the dealer, its $177 for the module and $225 for for the blower motor! But the dealer doesnt keep the fan in stock, but does keep the module. This leads me to believe the module are more likely to fail.

Im just trying to decide which to try to fix first. Gonna try to pull the module out today and see if it appears burnt up. But it wont stop freaking raining! Might test the wire leads too just to make sure they are getting a current.

Junkyard Module offer $10. Blower $ 15

1995 Riv wrote:

Junkyard Module offer $10. Blower $ 15

while there are a ton of junkyards near me, its almost impossible to find anything useful in them. There is a huge "immigrant" population in my town and they have raped anything useful from junkyards.

Parts from Auroras are the same my blower is from an Aurora. It is going to be ice storms up here next couple days. Seems like Auroras are overlooked here. If you have no power to purple wire on blower check fuses. If fuses good Check red wire going into blower control module for power it is hot at all times. You could also put 12 volts to purple wire on blower to see if it comes on.

If the 97 Rivi is anything like the 97 Bonneville, I had the same problem with it. All my problem was it had a bad relay on the firewall.

I got the module pulled out. Pretty easy, but difficult for me cause Im 225lbs with big shoulders and getting under that dash was pretty uncomfortable. Pics below. I believe its the same one the 95 rivs used, cause it doesnt look like AA's out of his 98'.

Got a new one on the way, but will test the leads this week when I go to install my N* throttle body. Ive checked the fuses repeatedly and they are all still good.

for what its worth, I ordered a new one on ebay. The sender sent me the one from the newer rivs....just like the one AA posted a pic of. I decided to try it anyways and it worked. Was about $80 with shipping on ebay, over twice what anyone around town had it for....So FYI.

I guess your part fit up in the housing and the connectors were the same ?

1995 Riv wrote:

I guess your part fit up in the housing and the connectors were the same ?

yes. The extra heat sink fins on the new one made getting it in a little more difficult than pulling the old one out. The blower housing gets in the way. but it will fit in there without removing the HVAC blower housing.

My blower control module went on my 98. Dealer wanted $177 so my mechanic suggested let's go to the junk yard. We found an Olds with the same HVAC head unit so he removed the blower control module from the engine compartment of the Olds. He is an old school mechanic that makes parts fit. When we got back to the shop he removed one fin of the heatsink so it fit perfectly. The heat sink has more metal & fins on the replacement then the original & also instead of the transistor it has a black module on the heatsink. Works perfectly, cost me $10 for the part & $40 for the labor. Any problems that could result from the different part?

I doubt it. But you'll find out over time, the only thing you you may find is the module will fail prematurely. But again i don't think it will be a problem.

Good move!

Bert

I'm having a problem where my blower for my AC doesn't work all the time. It won't work when I turn on the car and then when I hit highway speeds it'll just come on but not at full power. Then it'll go off again until I'm on the highway again. Anyone have a similar problem or know the solution to this?

Thanks, DJ

Blower motor control module. Look in this thread and you will see where it is located.

Hey all I was wondering if anyone has had a similar problem or knows the solution to my problem. I have a 96 Riviera and recently the blower for the interior has not been working. There will be no air coming through the vents at all and then when I get up to freeway speeds it'll just kick on. When I turn the car off and re enter later the blower will be off again. Also when it does work it doesn't blow air at full power, it seems like half of what it should be. I've checked the fuses and they are ok. I'm just wondering if this is something I should see the dealership about. Hope someone can help.

Thanks,
DJ

sounds like the blower control module is bad. they are ~$90 at the dealer, but rockauto should have them for a better price.

not sure why it would kick on when on the highway, other than just coincidence.

Or a junk yard for a used one. In one of the posts somewhere on here someone got one from a different car than a Riv. don't remember what car, it was a GM though and it worked.
Do a search for "blower control module or a/c fan resistor or something like that.
Can't remember. But it was an easy fix.

what all needs to be removed to get to the blower motor?? Any pictures??

thanks,

R

Just need to remove the panel below and foreword of the glove box.
Three 7mm screws, if I remember correctly, to remove the panel.
The blower motor is easily accessible.

In case you just want to replace the control module (most common problem), it can be accessed from below the dash. You don't need to take the entire motor out.

Well start to finish it took about 9 min.... thanks for all the help... Extremely easy!

Thanks,

Mike, did you need to replace only the control module or the entire blower unit?