No Electrial. Dead??

[danielbaldwin]

I have a 1948 (46?) Willys CJ2A. I restored/rebuilt the engine last year and all is fine. runs great. However, last week I left the headlights on after i turned it off, and the battery went dead. I tried recharging the battery 3x, but it wouldn't take a charge above 3.6 volts. The local parts store (Rebee's) replaced the 8 month old battery with a new one. It tests a solid 12 volts new, out of the engine. However, once installing the new battery I am back to the same problems as before. Absolutely dead. No starter, no lights (with the key on or off), no horn, nothing.

Anybody have any ideas?

Dan

[LarrBeard]

It's hard to troubleshoot electrical stuff from just an email, but:

A. Since things worked well for a long time, I'm going to assume this isn't a miswire somewhere in the 12-volt conversion. I'm also guessing it's not a pinched wire. Did the new battery spin things and run when you put it in? Does the new battery take a charge?

B. Whatever is happening is discharging the battery, and since you did not mention any spark or pop when you installed the new battery, it is a fairly low discharge rate.

C. With everything off, the only thing hanging on the battery is the alternator and its regulator (either internal or external regulator). Pull the alternator and regulator (if its external) and take them to the auto parts store. Most Auto Zones and O'Reilly type stores can check alternators and regulators.

Let us know what you find.

[danielbaldwin]

LarrBeard: Well, do I feel like a dummy !!! After reading your great directions, I went back out and rechecked the voltages. I quickly realized that I had a good 12.5 volts D.C. between the battery terminal posts, on the starter terminals, and everywhere else, but no ground on the ground ( - side) strap. Once I removed the ground strap, a small back plastic cup fell off!! It appears that I had somehow forgotten to remove the black plastic cup off the new battery negative side when I installed it. Once removing the plastic cup, all is well.

If you ever want to drive a weekend mechanic crazy, just insulate the negative post of the battery and reinstall the negative (ground ) strap. It will appears that nothing operates, but you have good battery everywhere. Ground straps are a pain in the ***, but physically required. LarrBeard, thank you for your directions.

signed, weekend mechanic, in need of "Mechanics for dummies" manual!

dan

[LarrBeard]

You've got to do a lot better than that to get on the "silliest things" list!

Glad you found it and I hope that that is the only problem. The fact that the old battery was down to 3.6 volts suggests either a really bad battery failure or a long term, slow, discharge.

I'd keep an eye on things for a while to make sure that there wasn't some other reason for the original failure.