electrical problems

Bad battery terminal connection to the battery.

Clean the terminal. Repair it so that the hole is round; often people tighten the things enough to make the hole oblong or oval. Get shiny metal to shiny metal and tighten it just enough so that you can't rotate the terminal on the battery post by hand.

You are describing a main battery cable end gone bad or loose. Jeeps are sneaky about the ground going bad where it bolts to the engine and where the main cables connect to the solenoid.

Sometimes if you try it a few times when it goes bad, the bad cable end will heat up so a careful feel of the wire ends can sometimes find it.

You can also track it with a multimeter looking for voltage drops. If you get it running and turn on everything like lights, wipers, heater you can 'walk' a meter looking for a volt drop.

You start with the meter on volts and put the probes on the battery posts. You then run one, say the negative first, to the clamp, then to the loop on the other end of the cable, then the bolt, then the block. You then do the opposite using the positive probe to 'walk' while leaving the negative on the post. Go to the cable loop at the solenoid, then the nut, then the post. If the volts drop more than a couple hundredths anywhere, you have found a bad connection.

When my Jeep does that, I just figure 'all' the main battery cable ends need cleaning so I go for it and just take them off for a clean.

Mike

I forgot to mention the body should be checked with the meter walking along in volts also because they lose grounds easy too. The solenoid needs to be grounded to turn the starter so nothing would work if the ground strap or cable connection arcs bad.