1992 Mustang LX Electrical Issue

samotrx7 · 02-23-2008

My sis's mustang is having a problem electrically. I notice that when I connect the battery cable to the post it sparks even with the key off. We tested the battery and it passed I haven't tested the alternator at autozone but I had the car running and removed the cable and the car stayed running so I assumed it was fine. We were driving it home today at night when the car decided to jus stop running and the battery light came on. All the lights seemed to be working fine everything was goin like the battery wasn't the problem. We decided to jump it anyways, it started and we were off when not even 20 seconds later it shutoff again same thing. I pulled it home with my mustang when the rope snapped, we decided to try and start it without a jump and it cranked right up and drove home the rest of the way no problem. Have any of you guys experienced this? It's like something with the electrical is overheating and cutting off fuel/spark? to the motor and than when it sits and cools it runs fine. If it were mine I wouldn't care but since it's my sis I need to figure out whats goin on with her ride. I appreciate any help/opinions from you guys.

genolx722 · 02-23-2008

maybe the coil? my brother had an s10 that would do that. you could drive it about 10 mins, then it would shut off and if you waited ten min, it would start back up and drive for about another 2 min until the coil heated again. just my thought. the cable is always going to spark a little because of the ecm

ethangsmith · 02-23-2008

Yes, you will always have a spark when connecting a battery back up. As said above, the computer is always on and takes a small, small amount of power. Also, since it is a 92, the airbag system takes a trickle of power also. As for the stalling, I have found that whenever mine stalled or shut off, it would always illuminate the battery light. That is because the car was running and the key is still in the run position. However, the alternator is not throwing a charge since the engine shut off, thus illuminating the battery light. Not saying your stalling couldn't be caused by an electrical issue, it certainly could be. Best and cheapest thing to do right now would be to check all of your wire connections. Pop each connector apart and clean the terminals and put some dielectric grease on them. Check your battery cables to make sure they are tight. A loose ground wire could cause stalling, as could a faulty connection. If you don't find anything and it still keeps acting up, I would almost suspect an ignition fault. The 90-93 DIS system seems to have some issues with spark cutting out. If the ignition module is failing or poorly grounded, it will cause stalling.

samotrx7 · 02-23-2008

Where is the ignition module located? It isnt the one on the driver's side front of the motor is it? Could I get it tested at autozone or anything?

turboeeyore · 02-23-2008

test the alternator while your at it.

ethangsmith · 02-23-2008

Since your car is a DIS ignition car, the ignition module is located on the intake. It is a rectangular grey thing mounted with screws to the side of the intake. The module itself cannot be tested really, but if it is faulty, it may throw a code, which can be read and interpreted. I agree, while at the parts store having a code scan done, have the alternator tested.

samotrx7 · 02-23-2008

I'll do that tomorrow, I'll have the alternator tested. But as far as testing the car I don't know why but the autozone over here has told me that they only test 96-up cars since they have obd-II.