fan or compressor?

[yucatec]

Dear Gurus,
The air on my 89 GM is acting uip. First a whoosh, then it comes. Sometimes, nothing, no matter what the fan setting. Is this a fan going bad or - ugh - the compressor?
Donald McCaig

[Blaze86Vic]

I think we need a more detailed description here. I had to rebuild my control box because my controle door came unhinged, so I know exactly what they look like inside. I bet you have the door issue. What happend to me, was the air would kinda go to where I selected it to go, but it would always come out the vents. Now I have a bolted 3" hing, I don't think it's going anywhere for a long time.

[gadget73]

Can you hear the fan running even when no air comes out?

[yucatec]

Dear Gurus,
no. Can't hear the fan running when no air cmes out. Also,it's erratic. When the AC works - usua;lly - i works fine. I'm afraid this is progressive. Donald McCaig

[Blaze86Vic]

As confusing as the simptoms are it sounds like you have a wiring issue. Just a guess thoug. Check the continuity from the ground wire on the compressor clutch to the negative battery post first.

[gadget73]

Sounds more like a fan problem to me. Either the fan motor is dying or the switch is failing. If I had to take a guess eitherway, I'd say the brushes in the fan are worn and are making intermittant contact. Next time it fails to work, check the voltage on the blower motor. Its under the hood on the passenger side and has a 2 wire connector (orange and black IIRC). If it has power and doesn't run, likely the motor is toast. Try whacking the motor with something and see if it comes on.

[Blaze86Vic]

:stupid:

I like his guess better than mine

[trwp72]

A/C motor

Another problem with the A/C blower motor is it has a fan relay... if it is not running, tap on the relay first, (it is usually mounted right next to the fan motor on the A/C box housing...) I replaced two motors before we figured out it was the relay.. as it was intermittent.... So check the relay too.... Tom....