So my 68 had been sitting for a while due to swapping axles. Finally get ready to fire it back up and I put the battery cable on wrong. Turned on the switch and melted the wire going from the hot terminal of the battery to the alternator. Killed it, disconnected and word in a new wire. Got the battery back in and nothing. All lights and accessories work but no starting.

Tried different batteries and checked wiring and everything seems ok. Now here's the deal. The jeep will fire and run fine when jumped. It will be ok for a while and I can shut it down and restart it no problem. But if it sits for a while without being run, maybe an hour. It won't start again without being jumped. Then the process repeats.

Batteries charged and tested fine, think I fried my alternator when I hooked the battery cables up backwards? All wiring looks fine from starter to frame and engine grounds. Any ideas?

Thanks.

How was the battery tested? Voltmeter? Load tested?

What kind of windshield wipers?  Had a Gremlin that did that.   The fuel pump was a dual diaphragm type. When one of the diaphragm went bad that would happen.

One of your ground wires looks okay but isn't.

The heat from the running is expanding the wire just enough to contact, jump is providing just enough extra to bridge the wire break.  When cold its breaking the ground connection.  Can happen with older tube style fuses also.

Your multi meter is going to get a workout finding this one.  Good luck.

Pull starter and alternator...have them tested. If external regulator is used, test it too.

Clean/grease all frame/body ground cable ends with wire brush, inspect for damage, replace if damaged.
Clean/grease all battery cable ends with wire brush, inspect for damage, replace if damaged.
Clean/ grease all the connectors on starter, solenoid, alternator, etc
Use "superlube" or other silicon dielectric grease when reassembling everything.


_

It may have been a bad ground on the alternator. Took in into town to get it tested, tested fine. Put it back on and jeep seems to be firing up normally. I'll update this thread if it comes back.