Cadillac Repair: a/c fuse, jumper wires, fuse box

Question
i own a 1994 sedan deville 4.9 8 cylinder. when you start the car the a/c will blow nice cold air for about 5min. then blow the a/c compressor fuse in the fuse box under the hood. the vehicle is in nice condition but i have only owned it for a week so i have no idea when this started. it drive good and seems to have no other issues. thanks

Answer
Hi Noel,

    Fuses blowing could be for several reasons.

1) If the clutch is cycling and the fuse blows there could be a wire that has rubbed through and grounds out on the frame or engine for the clutch circuit.
2) The clamping/anti-spiking diode in the clutch circuit might be starting to short out and needs to be replaced.
3) The clutch coil might be shorting out or using too many amps to hold the clutch engaged. There is a spec but not sure what it is off hand.

    If you can duplicate the problem then when the fuse blows unplug the a/c compressor connector and install a good fuse. If it doesn't blow then the problem could be with the clutch coil. At that point if you use an ohmmeter on either wire terminal on the coil and to the compressor and if it shows a reading then the coil is bad and needs to be replaced.

    If you substitute a lightbulb like a halogen headlamp bulb with 2 jumper wires into the clutch connector and the fuse blows then there is a wiring problem. If the fuse is ok then it is a clutch coil.

    Sounds like your mechanic might need to look at this because special tools would be required to remove the clutch coil. Bill