Electrical power loss

Using my 69 CJ5 as a daily driver- driving along with no issue then blackout - nothing electrical would work. Let it sit for a few minutes then the idiot (amps and oil) lights would show but when I turned the key over everything out again. tried several times until nothing would light. Pushed it off the road. Let it sit all day. Got in tonight and started right up no issues. Driving home less than 5 miles - blackout twice but restarted within seconds. Any ideas where to start?

I know there is good ground.

 

Last time I had issues like that the battery had a dead cell. but I would check the main power and grounds for the battery first.

 

Thinking about a new wire harness - painless appears to be good option?

 

I know you said good ground but figured id mention it. I would check your ground strap that goes between the frame and the motor when I bought my jeep I had to replace mine since mine was barely hanging on by a thread and ready to sever. http://walcks4wd.com/ground-strap-engine.html I got mine from a local Battery store. other than that id check for loose connections along the path from the battery to the starter and ignition switch. or maybe your ignitions switch is going out.

 

Anyone know where the circuit breaker is located?- wiring is stock - never knew of a circuit breaker. would be a great place to start.

 

Sounds like a battery issue. I would check your battery cables and battery clamps. Also check your battery post for corrosion build up.

 

I had the same issue whenever I would tow my boat trailer with the lights on. Could actually hear the breaker trip. Replaced the light switch and breaker and it hasn't happened since. In my case I think the breaker was getting tired and the extra load from the trailer lights pushed it over the edge.

 

The circuit breaker being talked about has no effect on the starter cranking over the engine. It's not in the same circuit. A bad cell in a battery will not recover while sitting as your car started back up after sitting all day. A total black-out and shut down (meaning not even starter power) would more likely be caused by complete loss of power from the battery due corroded cable connection, cable ground strap connections, internal connection inside the battery. These type of connections can recover when setting over time and cooling down but don't normally last to long. Heat causing expansion which causes disconnect is common in old circuits.

 

2x

Usually the battery posts or battery end of cables or both. I'm not sure what percentage of new batteries are bought because of cable/post corrosion, but 30 to 40% wouldn't surprise me.

 

I would replace the battery cables first. They can get corrosion around all the wires inside the insulation and cause problems. Check battery too

 

Don't throw away the flashlight because it needs new batteries....

 

check the wiring harness plug by the battery between engine. drove me crazy for months until found it and cleaned it . would do the same thing. it's a big plug.