electrical problem

David93

New Member
Apr 28, 2003
17
0
0
Hebron, IN
Suddenly the engine cut out while accelerating. When I popped the hood, the positive battery terminal was melted (molten metal on top of battery) and the battery terminal was partially melted as well. What could have caused an arc like this? Also, what else down the line could have been damaged? Obviously I will have to replace the battery and cables, but what was the cause and should I be worried about the computer etc?
 
Any damage has already been done. The computerhas its own voltage regulator/protective circuit, so it should be OK.

The possible culprits are the hood shorting out against the battery (look for burn marks on the hood) alternator with an internal short or the starter solenoid shorting out and making the starter run continously.

Word of caution: When working with automotive circuits, always disconnect the battery ground first and connect it last. That way if you short the postive lead to bare metal, you won't make sparks because you have no ground path for the power.

If for any reason you suspect the starter solenoid and/or starter, place the transmission in neutral or park and set the parking brake. That way when you put the new battery in, you won't get run over by your own car.

Disconnect the alternator prior to installing a fresh battery. It would be a good idea to put a test light in series with the alternator power feed and the starter solenoid where it connects. If it lights up, the alternator is suspect and should be removed and checked by your local auto parts store. Most of them will do it for free.

Don't have a test light? then leave the alternator connected, connect the battery postive terminal and then touch the negative terminal to the negative battery post. If you get a big spark, then unplug the alternator. Touch the negative terminal to the negative battery post again and get a big spark, you have other problems. Start pulling fuses and looking for bare spots in the wiring leading to the starter solenoid where everything gets its power feed from. The starter solenoid starts to be suspect at this point.

The last suspect item is an alternator that has a bad regulator in it and puts out an overvoltage. This can overheat the battery and burn out things. Pulling the alternator off and having it checked is a good part of your repair plan if you get this far without finding any damaged wiring.