Ok, so the blower motor quit working in all speeds. Checked fuse panel and found the fuse was blown. I cringed a little and said a quick prayer before putting in a new fuse. As expected it popped immediatly. I know there is a short somewhere. Anyone else seen this, I dont want to start checking circ uits if anyone knows a good place to start or a common place where the wire s rub.
It blew with the switch turned off or with the switch turned on?
The fox and hound can save a lot of time with this sort of thing.
--scott
Ok, so with the ignition on and ac off the blower motor operates normally at all apeeds. As soon as i switch on the ac it pops the fuse. Guess its worse than I thought.
That makes it easier, especially if it's a system that uses the same blower for AC and for heat.
Next step: if you disconnect the wire from the clutch solenoid on the AC compressor, does it still blow the fuse? If so, work back from the solenoid; there are probably at least two safety switches that have to be closed for the solenoid to operate. Those safety switches can be shorted to ground. The clutch solenoid can be shorted to ground too.
Some cars have a signal from the AC to the engine controller to let the engine know the AC is on, and some cars have a signal from the AC to the engine fan to turn the engine fan on continuously whenever the AC is on. Those things can also short to ground but are less likely to. I don't know if the Cavalier has either.
--scott
Nope, can only be three things on that car. Bad clutch on the compressor (shorted internally) Bad diode at the clutch electrical connection Short in the power feed to the clutch.
You will need a few fuses to do this testing or a self resetting breaker to plug in during the tests. The tests start at the A/C clutch and work back to the switches in the dash.
Unplug the connection at the A/C clutch, Test. Doesn't blow = bad clutch. Pull the A/C clutch relay to stop the ECM from turning the clutch on until you can replace the clutch.
If it still blows- Unplug the A/C compressor control relay, Test.
Doesn't blow = Bad diode or short in the front harness section, only 2 wires feed the clutch so it shouldn't be hard to find.
If it still blows there is a short in the harness between the A/C relay and the fuse.
Unplug the high pressure cutout switch, Test. If it doesn't blow follow the dark blue wire to the splice that feeds to the clutch and the ECM and trace it looking for damage.
If it does blow unplug the low pressure switch and test again. If it blows now look at the dark blue wire that comes out of that switch and goes to feed the high pressure switch.
If you disconnect the low pressure switch and the fuse still blows You will need to check the wiring harness under the dash for a shorted area and disconnect the plug from the back of the heater controls.
Sounds like a lot of work but I would bet on it being a bad clutch coil.
I remember a fairly common problem, but not necessarily with this specific car. Oil leaking onto the AC wiring will eventually destroy the wiring insulation, and the wires will short. Unplugging that connector might disturb the wiring enough that the short will go away temporarily, and that can mislead you into thinking it's the clutch, and not the wiring.
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