hey my 1991 cavalier sedan has an electrical short, the ecm fuse keeps poppiong everytime i turn the key to on. i removed the radio and glove box to see behind there, looking for a chafed wire or something but couldnt find it. does anyone have any tips for finding this? i have a multimeter and test light but not sure what i would be looking for.
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Have you looked around the ignition switch for any bare wires?
The ignition switch itself could be at fault.
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itmdtr
You need to find out what components are on that fused circuit. You will need to find wiring schematics for your car to determine that. If the ECM is the only unit on that fuse then the short circuit to ground is either somewhere between the fuse box and the ECM in the wire or in the ECM itself.
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sparky
don't use the test light when checking wires that go to the ecm!
use a computer safe digital multimeter
check that you have not connected the earth on your radio to the lighs live wire in your car this can be tested first just pull out radio leaving all wires attached and replace blown fuse where needed and with everything switched off put a live tester to earth and test your earth wire on radio no light should light up now switch on your lights on the car with the tester still connected if now the tester lights up or fuse pops again means you need to re earth because you have connected to lights live wire so you need to re earth as a lights live wire can look like and test as earth without the ignition on and most off time being a black wire can really be offputting allways use this method by hooking up your testlamp these are cheap to buy just connect the croc clip to earth and the other end being the probe you use to test the earth wire on your radio i have made this mistake a few times hope it helps pal
thanks but thats not the case. a mechanic friend of mine is supposed to come look at it for me as the damn car is still down after 2 weeks or so.
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Are you sure the ECM is still good?? Had the same problem in an S-10, fuses kept popping and the truck would shut off...... the difference is that the truck would crank for a brief period of time.
I changed the ECM and that solved the problem, it was a mere 20 bucks, and alot of headaches, lol
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i own 2 of the same car, so i tried the ecm from the other car which runs perfect and it still didnt work, ive traced the problem down to either the ignition control moduale or the coil packs, but thanks for the input :)
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