A/C electrical problem

Ehab · 05-02-2001, 10:05 AM

Hey all, today was a hot day in Boston. After using my AC for 10 minutes, the air blower fan stopped but everything else kept going. Fuse 6 was busted, so I replaced it, then as soon as I turn the AC back on, it blows again. This indicates that something else is shorting the circuit as soon as I turn the AC on ... anyone with previous experience? I need to know what is the most probable culprit (which part is burned out)

Thanks.

------------------
Lock Stock '84 944 and two smokin' tires ...

Mrmerlin · 05-02-2001, 02:44 PM

Quote:

Originally posted by Ehab:
Hey all, today was a hot day in Boston. After using my AC for 10 minutes, the air blower fan stopped but everything else kept going. Fuse 6 was busted, so I replaced it, then as soon as I turn the AC back on, it blows again. This indicates that something else is shorting the circuit as soon as I turn the AC on ... anyone with previous experience? I need to know what is the most probable culprit (which part is burned out)

Thanks.

First question is the fuse that you replaced it with the correct one if so then there is a heavy draw on that system if it keeps b;lowin, find the relay that runs the A/C and remove it clean the contacts use some dielectric grease on the fuse and relay connections..Let me know if this helps.....Stan

Porsche 951 Fanatic · 05-02-2001, 05:05 PM

Make sure there is nothing stuck in your fan! if its got something in there since it cannot spin it will blow the fuse

good luck

Ehab · 05-02-2001, 09:02 PM

I'm so glad that this didn't take long to fix. After redrawing the circuit from the Haynes Manual, I found out that the only thing that could short things out is the 'evaporator fan', which I think is the same as the coolant fan.

To my luck, I found out that relay III and relay VI are the same, where the III is the AC relay, and VI is the rear window defogger.

I switched the two relays, and voila ... it worked again, so obviously, the AC was shorting the circuit. I opened it, and the connection was bent and hitting the ground ... so it was the problem, I bent it back, and now it works again, so I put it back for relay VI, for the rear defogger (which I don't really use that much)

Thanks all for the comments and help.
Ehab