'91 c2500 350 AC and Alternator questions

[Bob57]

I recently got this truck from my dad. He has had trouble with AC blowing out dash vents. after reading several threads I took the ashtray out to the see the damper motor. Well to that I dropped the elect. trailer brake controller. When I started the engine the air blew out these vents like it did from new.
Is it possible the elect. brake controller be causing havic on the AC controller or damper motor.

I also had the brakes worked on (master cylinder) and the TB cleaned.

When I got the truck back I noticed the in-dash voltmeter at 18 volts. Had the Alt. tested at auto zone still in the truck alt. checked bad and I was told the battery not quite enough power at 550cca for the truck, so I got one with 750 cca. I cleaned the cable, and replaced on the battery. After installing battery and alt. I still show 18 volts on indash meter.
With engine running I test the voltage on battery and I get 14.28. I had left the voltage regulator wire off when starting the truck and seen the voltage at 15 on the dash meter.
Is this a bad voltmeter or another problem?

[2000CAYukon]

Originally Posted by Bob57

I recently got this truck from my dad. He has had trouble with AC blowing out dash vents. after reading several threads I took the ashtray out to the see the damper motor. Well to that I dropped the elect. trailer brake controller. When I started the engine the air blew out these vents like it did from new.
Is it possible the elect. brake controller be causing havic on the AC controller or damper motor.

If the actuator has never been replaced, it could just be tired. At least 15 years old. The one on my 90 will have to be replaced before I need the defroster again.

I also had the brakes worked on (master cylinder) and the TB cleaned.

When I got the truck back I noticed the in-dash voltmeter at 18 volts. Had the Alt. tested at auto zone still in the truck alt. checked bad and I was told the battery not quite enough power at 550cca for the truck, so I got one with 750 cca. I cleaned the cable, and replaced on the battery. After installing battery and alt. I still show 18 volts on indash meter.
With engine running I test the voltage on battery and I get 14.28. I had left the voltage regulator wire off when starting the truck and seen the voltage at 15 on the dash meter.
Is this a bad voltmeter or another problem?

If it is under 16 after startup with the wire properly connected on the alt, then you have no problems. Over 15 at the battery could mean a bad regulator.

//2000CAYukon

[Bob57]

first, thanks for your responce.

I left out something yesterday, the battery wire from the alt. has black faded ring about 2 inches from from the alt. and its not like the blk line on the wire from battery + terminal to junction block. I thought at first tape but no adhesive there. I don't know what to make of it, seem to me like fuse link should burn before leaving that mark.