v8 cj7 solenoid getting red hot

78custom

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Joined
Sep 25, 2005
Location
wilmington
i have a 79 cj7 with a 360 swapped in place of the 304. the starter solenoid is getting smoking hot and actually melting the insulation off of the wire leading to the starter. the ground wire that is also grounded at the starter is also getting hot. this is happening while trying to crank the vehicle. i have moved the ground around and found the best spot being on the starter mounting bolt. i have replaced the starter thinking it had a shorted turn and it got better. i have gone thru several solenoids and the problem still exists. can someone point me in the right direction? thanks
 
the engine grounding strap is on the engine mounting bolt. i have the negative lead from the battery attached to the starter bolt like factory
 
Yeah my new one would stick every so often and the starter wouldn't stop until you gave the solenoid a good wack
 
Sounds like something is not wired right or it is bad. Your solenoid is carrying the the amp load from the way it sounds. It should only see a trigger and pass the load through it. Make sure something isn't looped in wrong on the activate wire or the solenoid ground. These are solely independent, or should be of the starter load. Bad solenoid or solenoid grounds don't allow them to completely close too. Do these guys use a starter mounted solenoid or independent fender or firewall mounted unit?? I can't remember.
 
Last edited:
WARRIORWELDING said:
Sounds like something is not wired right or it is bad. Your solenoid is carrying the the amp load from the way it sounds. It should only see a trigger and pass the load through it. Make sure something isn't looped in wrong on the activate wire or the solenoid ground. These are solely independent, or should be of the starter load. Bad solenoid or solenoid grounds don't allow them to completely close too. Do these guys use a starter mounted solenoid or independent fender or firewall mounted unit?? I can't remember.
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They are fender mounted.
 
My 79 CJ Factory 304, has the Motorcraft Ing., & starter solenoid on the fender well. Driver side motor mount has ground to frame. Battery is grounded to a head bolt on the battery side. It's all Factory! I've replaced 2 starters, but never changed the solenoid, & never had a problem.
 
I'd try running a ground from battery to fender, near where Solenoid is mounted. Small wire as ina 12 gauge. clean off the paint, some die electric grease on the connection, and terminal. Clean and do the same to all grounds as far as cleaning, and using die-electric grease. wire brush the ends. Also do the same with the mounting bolts or screws for the solenoid. Take away any issue with a bad ground.Very possible the heat may have already caused damage to the new solenoid, and or, the cables. What ever is going on, it does sound like a grounding issue
 
High resistance and wire size issues are the cause for melted or hot solenoids with the exception of extremely long cranking time. Do a voltage drop test to the solenoid and then the starter and see what you find. The solenoid itself is going to use very little current to activate, so a significant ground isn't needed. If your concerned about a ground issue do a ground drop. You shouldn't see more than .5v

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