Electrical Problem

My son got a 1993 Pontiac Transport recently. It's a clunker, but it was getting him around. All of a sudden it started running real rough. When I checked it in the driveway, it would start with a jump, but would not accelerate. If you put it in reverse it would shake, sputter and stall. If you put it in drive, it would inch forward just as you would expect it to. We had the alt checked, and it checked out good. We found one vacuum line collapsed and replaced that. I also found some wires underneath the car that had been spliced together but were now burned up and coming apart. Someone had taken two red wires from inside a wire harness and spliced them to one smaller gauge wire and had it connected to the starter. There was another wire coming out of the harness that was also connected to the same terminal on the starter. I thought that maybe the splice was causing the problem so I re spliced the two red wires back into two singe wires and reconnected all three back to the terminal that I took them off of. After we started the car, we got a puff of smoke from the starter area and also from another area that I couldn't seem to locate. I'm not sure what damage I did, but now I don't know what to do about those wires.

 

Keep in mind that wire gauge sizes that might be downsized or if fuseable links have been eliminated, could lead to melted wires or even a fire. You probably really need to research the wiring diagram for this circuit.

Are you at all remotely familiar with basic starter circuitry? Or are you familiar with looking at wiring diagrams and working on electrical or electronics? If not, correcting all this may be something over your head.

 

Sounds like a direct short. I'm guessing that you got some wires crossed when you respliced them. I'd trace out the wires to see where they go. If you can't trace them back, I'd test them out. Seperate them first and turn on the ignition. Obviously the wire that gets voltage comes off the ignition switch. I'd test the rest to ground. Use an ohmmeter and see if any of them have 0-very little resistance to ground. If this is the case, you had a direct short. Taking a look at a wiring diagram for your car's ignition circuit can also help you trace things out.

I'm an electrician, not an automechanic, but my first thought was transmission, not electrical.

 

I'm certainly no auto mechanic. I just was able to look at the splice and see what was done. I simply re did what was done before only neater. The car was working properly before the splice was discovered. I simply used logic to say that since the car is now not working properly and the splice has all but come apart, this may be the problem. I have been searching the web for a wiring diagram, but not having much luck.

 

If you have no luck online, I think I've heard of a place that old-timers call a "library". I'm only teasing. I admit that I've gotten so dependant on the internet that a lot of times I'll waste more time searching for answers online than it would take to walk 3 blocks to my local library and look them up. If the library doesn't have the manual for your car, you're best off investing the $10 to buy one at your local automotive store. It'll be money well spent! I'm assuming that with a '93 you can still do a diagnostic scan with a simple wire jumper. A repair manual will explain how if you're unsure. It'll also have a troubleshooting section that gives possible diagnosis for different symptoms. Once you get the wiring fixed and if it's still not running right, I'd start there. Just make sure you disconnect the battery before running a diagnostic check to clear the memory of old trouble codes. Obviously you'd have to start the car up again and put it into forward and reverse to get the trouble codes pertaining to your problem to show up again.

If you already knew all of this then I apologize. I'm no expert myself, but I haven't seen any experts respond yet so I thought I'd suggest what I would do. Hope this helps!