hi

been trying to figure this out with the service manual

89 iroc.

fan came on last week. noticed the other day it wasnt coming on in any position.

checked 25 amp fuse = GOOD.

next book says NO BLOWER to do voltage check at motor.

says put on VENT then fan on HI and check voltage at fan motor. should be battery voltage but nothing there.

says next with no blower to check hvac controls in dash. 12v IN is brown wire = 12v GOOD.

it then talks about the brown with White wire. any pos but off should have 12 v and YES that is good too.

tells me to check wires going into Hi Speed resistor.......all voltage checked good.



gave up last night,


for giggles this morning I did get my power supply down and put 12v to the blower motor and it does work.





today i plan to test the switch but from the symptoms and result according to the manual I cannot find an issue.


one more thing.


manual says test motor with switch on HI and I dont get voltage...;.

BUT if I put the switch on OTHER positions not high I DO get some voltage to the motor but it was like 11.89 on my meter.





ANY IDEAS


AND if I do need a head unit or a switch is aftermarket my only choice?

 

Hi speed relay.Did you check it? Its by the blower fan.

 

i havent tested that just yet.

but I will later today.

 

Looks like it was the relay based on testing.

I ordered one from prime. I wanted the AC delco one.

Will finalize once installed and tested.