1998 Riviera Blower Motor Failure

Hello,

I own a 1997 Riviera and love it! I recently had a failure of my heater blower motor. I found in this forum the tip that it might be the blower control module under the glove box. I ordered a new one for around 95$,installed it today and the system was working again fine for about 20min. I stopped the car, came back now after 20min and I have the same problem again.
Could it be maybe also the blower motor itself that is faulty and causing the module to fail?
Thanks for any help!

I would try recalibrating the HVAC system first. Here are a couple relevant posts I found in a thread about the 98 Park Avenue. Sorry I couldn't find anything Riv specific, although it may be on here somewhere!

Quote :

If you do replace a mode or blend door or programmer or control head, know that you should turn OFF your HVAC and then turn on your car. Leave it sit in the on position for the car/off position for the AC for about 3 minutes. All the door positions will calibrate.

Quote :

From Pete at: justanswer.com

O.k.,this does sound like the heater/ac temp actuators are out of calibration.This will occur if they did any reprogramming or the battery died at one point or disconnected at any point.The calibration procedure has to be done by a dealer or repair facility that has a scan tool that will plug into this model here and that can communicate with the heater/ac control panel.The scan tool is then actuated to perform the actuator calibration procedure.This usually takes less then 5 minutes to do once plugged in.

I would ask the dealer if they did this and if they did not ask them to do this as this should correct the issue here.If this was a heater core issue you would be stuck blowing the same temp all of the time and this is not the case here.The actuators need calibrated.If the dealer will not do this then another repair facility with this type of scan tool will need to do this for you and all together once in the shop will take less then a half hour to do.If another shop has to do this I would then ask the dealer if they will pay for the charges to have this done since they didnt do it.

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I've had to recalibrate the system on a Silverado a couple times. I would do it before replacing modules, and after that I would pull a bad module, open it up, and make sure the electronic traces aren't covered in grease. GM is bad about putting gear grease in places it doesn't need to go. I've fixed 3 modules just by cleaning them and recalibrating the system.

I also think recalibrating the HVAC system might do the trick. Try it first please and let us know
Good luck brother

Thanks for the fast replys! I did turn the system off as described above for 5min Then on again and there was no change. But then I pulled the bigger connector on the module itself (purple and black wire), plugged it back on and the blower is working now again. Maybe I have a problem in the connector or one of the cables.

It's also possible this isn't the right procedure for the Riviera.

Yes. I have an Actron Scan tool for GM. Maybe I will find something there. Thanks!

Parkermole wrote:

Hello,

I own a 1997 Riviera and love it! I recently had a failure of my heater blower motor. I found in this forum the tip that it might be the blower control module under the glove box. I ordered a new one for around 95$,installed it today and the system was working again fine for about 20min. I stopped the car, came back now after 20min and I have the same problem again.
Could it be maybe also the blower motor itself that is faulty and causing the module to fail?
Thanks for any help!

If your Riviera has the original OEM blower motor (made by Harrison Radiator - there will be a label on the blower motor housing) it can be disassembled and repaired with common electrical motor hardware.  With the failure you are describing, you should remove and inspect the blower motor.  I suspect you will find an accumulation of dust from the wear of the brushes against the commutator.  I also expect that the accumulated dust creates a short circuit of some description. Also, your problem may be related to sparking and arcing in the dirty motor.

Disassemble the motor and use a vacuum cleaner to remove the dust.  On a site such as this: http://www.graphitestore.com/Carbon-Brushes/Brushes you will find replacement brushes that can fit to your motor. amazon.com is another source although their selection is not so broad. See https://www.amazon.com/carbon-brushes-electric-motors/s?k=carbon+brushes+for+electric+motors.  Measure teh cross-section of thebrushes, then get a pair that you can put inot the Harrison motor.  Do not worry too much if the brushes are too long, you can use a Dremel tool with cutoff wheel to shorten and polish the contact ends so they fit.  The new brushes'  length will compress the springs 2/3 to 7/8ths of the way and will capture the wire pigtail inside the compressed spring.

You can resurface the commutator by spinning it with your fingers whilst burnishing it with a pencil eraser, a piece of emery cloth if it is scored a bit, or a flat file if it is really bad but still functioning, then cleaning the gaps between the copper contacts. See https://www.youtube.com/watch?v=MkBLwUG_AdU for and example of a circular saw motor.  

Just an aside in case you are curious -- Harrison Radiator was reorganized by General Motors into part of its Delphi division in 1995, which was made independent company in 1999 and then in 2009, General Motors bought Harrison Radiator back from Delphi.  

Replacement motors such as from VDO work but are very noisy and somewhat smelly compared to the original Harrison.  I installed a VDO in my Riv temporarily while I rebuilt my Harrison, then put the Harrison right back in.

Albertj

Wow! Thanks a lot for that advise! Sounds like a plan.....

Parkermole wrote:

Wow! Thanks a lot for that advise! Sounds like a plan.....

You are welcome.  I did kind of get carried away.  The main point is that the OE blower motors in these cars are easily rebuilt.  They have rubber noise isolators and well balanced armatures.  A few minutes of work and you won't have to mess with it for another decade or so.

In the unlikely event you need to repair the armature, you can do that with common hardware and some non-conductive epoxy (most epoxies are non-conductive but be sure you confirm that, some are steel- or aluminum-filled).  Here is an example of such a rebuild accomplished with relatively crude hand tools and household epoxy: https://www.youtube.com/watch?v=Fb2IMdlKBiw - his greasing the outside of the sealed bearing is ineffective (if he does not know that, that is a problem), but as you can see the item works after repair. With those sealed bearings, one sometimes (but not always) can open the seal, clean out the bearing race (brake cleaner), repack the bearing with shop grease (I like Mobil1 or Lucas synthetic) and reclose the seal. Here is an example: https://www.youtube.com/watch?v=v6Jx-LIfZu8. The example shows openable and non-openable sealed bearings.

Albertj