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Hi all,

I have followed many threads here and now I'm stumped.

AC Blower worked intermittently, on & off when i would tap the motor. Transistor meter checked as good. Replaced Motor, issue gone for a day.
Blower motor suddenly stopped and did not move even with tapping. Slight jump when ignition turned on. Tested motor good, replaced Transistor, issue gone for 30 mins, next start up, no blower again. I hear the ac compressor start up and then stop after a few seconds. All buttons & selections work minus the blower speed selector ****. 40A fuse under hood also good.

What now?

 
Rep Power: 308

Leave the fan on, then grab the connector and wiring for the blower, and at the transistor and move them around while watching to see if the fan works or tries to while doing so. (looking for intermittent connection)

 
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Jiggled everything I could, nothing. I opened the glove box and observed when the key goes to accessories I get a slight momentary (.5 sec) spin from the blower.

 
Rep Power: 308

That is what happens when the TCO opens on a 7th gen.

Don't see many transistor issues with 8th gens.

Both do the same thing ??

Find the TCO and Ohm it out.

 
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The TCO is part of the transistor assembly correct?

 
Rep Power: 308

I'm not sure if 8ths use them still.

Silver color body with 2 leads, one from each end.

 
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I took out the just replaced Transistor and tested it. Good resistance & diode test. If a TCO activates, does it reset or is it a one shot pop?

 
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Also did a voltage check off the blower connector. Steady 14V regardless of the blower dial position. Also plugged in the old blower and got the same result, a short twitch when power is applied but no real spin.

 
Rep Power: 308

TCO is like a fuse, one and done.

I will try to throw some info together.

 
Rep Power: 0

Sadly it appears I may have caused the problem. I didn't reinstall the blower transistor assembly, leaving it hanging that first time. It appears that there is some ducting from the blower across the transistor heat sink. Without this air flow I burned up the new part. Exchanged, installed fully, problem solved so far. Lesson Learned.

 
Rep Power: 308

Oh yea, the heat sink part.

I think others have done that as well.

So your TCO likely did open.