This 93 Ford F350 7.3 has had to be jumped for some time to give it enough juice to crank. The longest it went between cranks was a week and a half. Today we were cranking it. The battery had four hours of run-time to charge yesterday. Waited for the glow plugs to warm up, turned the key, engine had just started turning, then *CLICK* everything went dead. No power to dome lights, dash lights, etc. The local shop, without looking at it, said they suspect a bad connection. All the battery terminals are clean. However, there is some discoloration on the battery cable insulation near the negative terminal on the first battery. All the fuses are good, in the dash and in the engine compartment. Any Ideas? Could we do harm to the electrical system if we try to jump it again? Thanks in advance.

 

welcome to diesel bombers warm up your batteries and load check them then look for loose or broken wires and cables check your cable ends sounds to me like a dead battery really dead

 

Is there an underhood lamp??

 

IIRC there's a relay under the hood that smokes batteries if it gets stuck. It was common on OBS gassers and the PSD's.

I'll see if I can dig up the write up about it somewhere.

 

you could also have a draw, (caused by that relay that chvyrkr mentioned) but also check to see if any lights are being left on. any accessories? plow? strobes??

 

Yeppers, cousin. Used a battery tester, and both batteries have a voltage drop. Just was concerned it was something else when everything in the cab lost power, but the interior lights started working again a day later.

Plan to buy a battery or two tomorrow. We expect that's the problem; I'll get my dad to post if isn't.

 

 

Please update.

 

Please update.

 

Closing, lack of updates.