My blowers were blowing just fine -then they started slowing down and stopped. And that's the situation for the last week -although sometimes, on first start in the morning, blowers will run for a minute or two then stop and won't start again. A/C or heat selected, no difference, no air.

What I've done so far ...
Checked brown wire to blower -got 12V.
Swapped out the CC microprocessor. No difference.
Opened up DBC10009, reflowed connections. No difference.
Replaced DBC10009, reflowed that module too, no difference.
Removed control panel, contact cleaner sprayed contacts. All lights on panel work properly and I can hear the blend doors and vacuum flaps moving as I change the settings.

ok I'm out of ideas ...anyone?

Larry

 

If they start and then slow to a stop, my thought would go to the bearings in the motor. As the motor runs they get warm and seize up. Did you notice any "bad bearing" noises?

 

Larry, it's probably your fusebox, if it can't provide enough juice to the motor it won't run, connect 12V from battery directly to brown wire - if it works, you'll need to redo fusebox(including cutting it open), if it doesn't then it's a blower out job and possibly replacing that Darlington or at least reflowing it but if you'll have it out, may as well replace them.

 

I'm leaning towards the control panel, I'll be swapping it out for a test today. I don't have the exact part, it's the same year (94) but the panel controls are a bit different. DBC11814 (VDP) vs. DBC11817 (Sovereign) Still, it should work for testing purposes, connector is the same.

Larry

 

Seems odd that BOTH would quit at the same time if that were the case Jerry ..CC was blowing an A/C gale when things quit so I know they were working together at the time.

Larry

 

The replacement panel didn't help. Same symptoms, blowers dead on all speeds.

Larry

 

Next move, look at the diodes & relays inside the blowers. I have some spare relays, will check in a day or two if they are suitable.

Larry

 

Got the blowers working again but the armature on one of the spare blower motors is seriously worn, along with the brushes. Any sources for a replacement fan motor?

 

Hy Larry, what you've changed?

 

New control circuit board components, transistor etc.

 

I cleaned and checked the fans... The motors, relays, and transistors seem to be working fine but the problem persists. I'll try to change the control unit too, hopefully it works. Is there any system that could inhibit the operation of the fans?

 

Giuseppe86 - Please describe the symptoms you are experiencing - there can be several issues than can cause the blowers to stop running. I believe on the 89MY cars the micro switch inside the control panel can be a problem and it too will have specific failure symptoms.

 

Ok, thanks! when I turn on the air conditioner the fans go to full speed but then slow down to a stop. This happens at any temperature. If set in defrost the fans go very slowly and if I switch from defrost to high, normal or slow they accelerate and then stop for a while.
I checked the output voltages from the board and the anomalies are: no solenoid is energized, the lower flap feedback and upper flap feedback indicate 0v unless I rotate the flaps manually.

Thanks
Giuseppe

 

I've verified that the defrost solenoid always seems energized, even though it's not set to defrost mode. From the blower controls comes out 1.2v voltage only in defrost and sometimes also in the other modes, but the fans always rotate slowly

 

When the fans finally stop, check you still have 12v on the brown w/blue tracer at the fan power connector that leads from the fuse box.

Your issue isn't one I've ever had ...my problems have always been with with cracked joints in the fuse box or circuit problems in the speed control board/components inside the blower housings.

While I believed the both fans were quitting, (which led me to assume it was a central control problem) it was in fact just ONE as the other had not been running for quite some time.

 

As well as the potentiometer that mounts the adjustment knob.