AC/Heater Fan control

[atis]

I stood over their shoulder... I dont trust the people at parts store. I have had a few issues with them selecting the wrong vehicle and I live 25 minutes away so running back to get the correct part sucks, that and I tend to know more about cars then they do which can be frustrating.

My rear control is AC only so its a simple single switch for rear blower control.

 

[gpracer1]

That is a standard unit. Should be gm 9378805.

Yup, looks just like the one in my 99.

Rockauto 1572547

 

[atis]

Thanks for the part number and company. I just installed the new part and I still dont have a front blower... so what do I check next??

I have replaced the following:

1) relay in the relay center under the hood
2) Blower resistor
3) Control panel in dash

I have tested the blower motor with a mechanics 12v test probe and it works fine. I checked the fuses located in the relay center and the ones on the side of the dash on the drivers side.

Suggests as to what to check next and where its located? My manual sucks for telling where things are. I get AC in the back using the rear ac control switch so I know the AC compressor and such is working fine.

 

[SunlitComet]

What relay under the hood and why to just refresh my memory? Have you looked into the possibility of a malfunctioning hi-speed blower relay malfunction? it is behind the glove box on top of the hvac housing.

 

[atis]

There is a relay labeled "blower" under the hood in the fuse relay center (driver side close to brake resevoir) thats the same as the starter relay.

Interesting, I couldnt find that relay in the book so that will be my next check. We had intermitent power to the blower plug when we tested it which is why I guessed the control panel in the dash....thats a nice $104 wrong guess. I would go broke if I owned a Pawn shop. LOL

 

[SunlitComet]

sure that was not the a/c clutch relay? there is supposed to be a 50amp **** fuse for high speed blower relay in there though. Unless something changed that is not reflected in the diagrams. I thought the 2000 Tahoes were supposed to be a carry over from 1999.

 

[atis]

Mine is a carry over. There is also a 50 amp fuse in that same box. It might have been the ac clutch relay...either way its good so I will check the one under the dash.

 

[SunlitComet]

Are you sure that was not the a/c clutch relay. there should be a 50 amp **** fuse for the high speed relay which was supposed to be on top of the hvac housing behind the glove box. The 2000 models were a carry over from the 99's right?

---------- Post added at 04:47 PM ---------- Previous post was at 04:47 PM ----------

Posted to late.

---------- Post added at 04:49 PM ---------- Previous post was at 04:47 PM ----------

Blower Motor Relay, High

Front HVAC Assembly



Behind the IP compartment box, on the HVAC plenum

 

[atis]

thanks, thats a tight spot to get too... figures. I had tried to replace the blower motor but couldnt get the same one I have...all the ones that were "listed" for the Hoe either lacked the screw mounting holes or had a 1 wire hook up rather then 2 wire.

 

[SunlitComet]

You remove the glove box to get at it.