2001 V70T5: Dead HVAC blower...

carboncow · Post by **carboncow** » 10 Feb 2015, 10:11

This is our 3rd car...doesn't get used much. Been sitting in sub zero weather for a month w/o starting till today. It struggled at first but settled down...then noted the blower was dead but the HVAC is lighting up...have not had time to put on Vida Dice yet.

30amp fuse is AOK
I've replaced the motor twice in 5 years on this car...always el cheapos that work fine but I replace due to squeeling bearings on turns.

I know on my Saab when the resistor would go it would just leave the fan on 100% full speed...so doubt that is it. No smell.

Anything to try or just a DOA fan?

Post by **regent** » 10 Feb 2015, 11:57

Check the electrical connector at the fan for loose/dirty/recessed pins.
I think VIDA/DiCE can read the amperage draw by the blower motor also. If it stays at zero amps, then I would try hard-wiring the B+ to the blower motor through some resistance (like a headlight bulb in series) - it could be that the blower's speed control is at fault this time, and not the motor itself.

If you are below freezing, condensation and/or debris could be interfering with the squirrel cage

carboncow · Post by **carboncow** » 10 Feb 2015, 14:03

Regent...good call! I put the car in the heated garage for about 5 hours and it the fan started right up. Something was frozen!

Not saying it couldn't have been the speed control but my experience had been the enginners design them to all fail at 100% on so the end user has at least something pushing heat/cool if there is a failure.

So I thought your 2nd idea sounded spot on and I think it was. Good lesson learned and always something new even after 25 years of DIY wrenching!

Post by **regent** » 11 Feb 2015, 06:10

carboncow wrote:...I put the car in the heated garage for about 5 hours and it the fan started right up. Something was frozen!..

I am thinking worn or 'hanging' brushes (don't know how many run-hours your blower has). The brushes probably 'shrank' even further in the cold and could not reach the commutator.

The biggest issues in our old cars are caused by electrons: As the car gets older, they do too, and then they get tired and eventually become a lot slower...
Slow Electrons + Extreme Clod = Loss Of Functionality