Air Conditioning Fuse Keeps Blowing

[Scott_SS]

Hi, I have an 83 Cutlass Calais that the AC fuse keeps blowing. Its not the compressor causing this as it blows the fuse with the compressor unplugged. If I turn the key on and set the HVAC to vent the blower motor works fine with no issues. As soon as you slide it over to AC the fuse blows and this is without the car running, just with the key on. Any suggestions on where to check first to find out the issue. Seems like a direct short. Is there a AC relay? I have been looking and if there is one I can't find it.

Thanks,
Scott

 

[L92 OLDS]

Hi, I have an 83 Cutlass Calais that the AC fuse keeps blowing. Its not the compressor causing this as it blows the fuse with the compressor unplugged. If I turn the key on and set the HVAC to vent the blower motor works fine with no issues. As soon as you slide it over to AC the fuse blows and this is without the car running, just with the key on. Any suggestions on where to check first to find out the issue. Seems like a direct short. Is there a AC relay? I have been looking and if there is one I can't find it.

Thanks,
Scott

Have you checked resistance from the green AC compressor clutch wire to ground with the AC off?

 

[Scott_SS]

Have you checked resistance from the green AC compressor clutch wire to ground with the AC off?

Hi, no I have not. How many ohms resistance should I be expecting.

 

[HAFROD]

Could it be the 4 prong plug in behind passenger side valve cover? Every G body I've owned has been melted. I'd check the compressor wire (green) to see if its pinched or bare spot too

 

[Scott_SS]

Could it be the 4 prong plug in behind passenger side valve cover? Every G body I've owned has been melted. I'd check the compressor wire (green) to see if its pinched or bare spot too

Thanks, for the reply. I did check the wires that run directly to the compressor and they looked fine. There is a relay with part number 10018449 that is on the passenger side near the blower motor and condenser. Is this the connector you are referring to? Its actually my father in laws car and he just left so cant remember if it was a 4 prong connector. We are going to order a new relay as looking up the part number it says its and A/C High Blow relay.

 

[Texas82GP]

Next time you have the car handy, set your multi-meter to check continuity and check to make sure the hot wire to the compressor isn't shorted to ground.

 

[Scott_SS]

Next time you have the car handy, set your multi-meter to check continuity and check to make sure the hot wire to the compressor isn't shorted to ground.

Thanks. Will do. I should be looking at it again tomorrow.

 

[L92 OLDS]

Hi, no I have not. How many ohms resistance should I be expecting.

Normally it should read an open circuit but if the green wire is shorted to ground (causing the blown fuse) it would read 0 ohms.

 

[Scott_SS]

Normally it should read an open circuit but if the green wire is shorted to ground (causing the blown fuse) it would read 0 ohms.

I finally got chance to look at it again. I replaced the blower relay and the fuse still blew. So I checked the resistance on the green wire and I get more than 0 ohms. So I traced the wire back through the harness and I could not find any breaks in the wiring. The wiring is actually in good shape. So I am not sure where to go from here. Could it be the A/C Pressue cycling switch or the HVAC controls? Any other suggestions?

 

[Texas82GP]

If you unplug the connector at the compressor and replace the fuse, can you turn on the a/c without blowing the fuse? I'm wondering if the clutch coil is shorting to ground.