Bricker Posted July 24, 2014 Share Posted July 24, 2014 Classic example of haste makes waste! I was in a hurry to swap out a dead battery in my MJ during a recent rain storm. Apparently I did not get my positive terminal down all the way, because the truck stalled after about a half mile and I noticed a small amount of smoke coming from under the hood. The hood made contact with the positive terminal and was arcing. Problem is now the truck won't start. I thought I may have fried the coil but it is getting spark. I have not had time to conduct thorough checks but I also noticed the headlights, radio, fuel pump are not coming on. I checked fuses and they appear OK. Does anyone know any obvious things/ways to identify this electrical problem?? My Comanche is a 4.0, 2wd, 5 spd. Thanks in advance Link to comment Share on other sites More sharing options...
1989 Eliminator Posted July 24, 2014 Share Posted July 24, 2014 Well. I would either assume the alternator is fried or the ignition solenoid because that is where current is being fed. The arcing was due to the alternator producing current and arcing to ground (the hood). So id check to see if the alternator is doing anything first. Link to comment Share on other sites More sharing options...
1989 Eliminator Posted July 24, 2014 Share Posted July 24, 2014 There are also a bunch of fuseable links by the solenoid that you should check. Link to comment Share on other sites More sharing options...
Bricker Posted July 24, 2014 Author Share Posted July 24, 2014 Thanks for the very prompt reply. I'll check those out. It does crank and spark so I figured that at the solenoid would still be good. Maybe it's one of those fuseable links between the solenoid and relays. I was not aware of those. Electrical diagnosing is my weakest area of auto related knowledge. Again thanks for the help Link to comment Share on other sites More sharing options...
1989 Eliminator Posted July 24, 2014 Share Posted July 24, 2014 Okay well to test the fuseable links, take a multimeter and set it on ohms or continutity and probe across the link. If you get an infinite reading in ohms or a no continunity reading then the link is broken. There are actully quite a few near the solenoid and relays. Link to comment Share on other sites More sharing options...
Bricker Posted July 27, 2014 Author Share Posted July 27, 2014 I was able to get my truck started today after a variety of checks. All my relays and wire links checked out. Using a multimeter with the ignition switch on I had power to the fuel pump. Frustrated that I may have fried smaller wires to these earlier mentioned components, I began checking wires under the hood. I then noticed the large ground wire/strap that runs from the back of the valve cover/block area to the middle of the fire wall was broken. It looked like it was burned and was broken all the way through roughly in the middle. There was enough slack in it to twist it together and crimp it. (I'll replace it with a new ground wire tomorrow). It immediately brought the truck back to life. The lights came back on, radio works and most importantly the fuel pump is operating. I had no idea that this ground strap was so critical, I'm glad I did not just start replacing parts without first doing checks with the multimeter. If you have problems with your fuel pump or other related electric quirks this ground wire is a good thing to check first! Link to comment Share on other sites More sharing options...
Jeep Driver Posted July 27, 2014 Share Posted July 27, 2014 Replace it with a 4 gauge cable with copper lugs and not another worthless strap. Link to comment Share on other sites More sharing options...
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