A '95 Chevy Impala Repair Advice
How To Fix a 1995 Chevrolet Impala with Major Electrical Problems
Your questions answered about a 1995 Chevy Impala that has an electrical problem.
This weekly Q&A session answers your questions about cars and trucks. This week explores a 1995 Chevy Impala that keeps blowing A/C fuses.
Question: 1995 Chevy Impala
I have a 1995 Chevy Impala with many hi-performance modifications but still smog legal. I had the transmission rebuilt a little bit ago. When the mechanic was reinstalling the transmission, an alarm with ignition kill went off, and we didn't even know the car had an old alarm. We removed the alarm and have no low beams headlights and the A/C keeps blowing fuses instantly once turned on.
I'm not so trusting of that shop because they looked at it afterward and said the issues were not related and they didn't know why I wasn't getting lights. They said they tested the lights and was getting power out of the switch but for some reason not to the light. I know an electrical guy who works for Dodge; he tested a few things and said the switch was bad and was getting no power out of it.
We are going to replace the switch but I'm wondering if there is a short in the harness somewhere by the transmission or located somewhere in the harness related to the removal of the transmission that would affect the headlights and A/C?
I guess I'm just looking for an educated guess of where to start looking for a short. Is there wiring removed and reinstalled in a trans removal that would affect the lights and A/C?
Answer:
The first mistake, and it's a big one, was your mechanic installing the transmission with the battery still connected. Cars can catch fire when a transmission is taken out without first disconnecting the battery.
Since the problem started when the transmission was installed, that is a good idea. A lot of times a wire(s) get pinched between the engine and transmission and cause a dead short. So, carefully check the harnesses in that area first. If there are no wires pinched then you will have to start looking elsewhere.
Since a short circuit can be anywhere, you will need to get a wiring diagram, a test light and a DVOM. Start by unplugging everything feeding off that fuse and retest. If the fuse doesn't blow then one of the things you unplugged is the problem.
Start plugging things back in, one at a time until the fuse pops. Then you have found the problem. If after unplugging everything you still have the short, the problem is in the wiring. You will then need to use the wiring diagram to break the break the circuit into pieces and check each section.
Once you locate which section the short is in, then you can break that section down until you pinpoint the short. It's not difficult, but it can take some time to locate. You just need perseverance and a little common sense to find it.
For more information you can read Electrical Trouble Shooting for lots of tips and tricks locating an electrical problem.
That's all for this week. Feel free to browse the archives for past topics and other resources. And, as always, if you are stuck and need an immediate answer you can always call Vince on the phone.
