Here's what its doing. Typically it'll start and charge no problems. Every now and then though, I'll stop for gas or something, and it'll start having trouble starting. Typically low battery symptoms. This weekend, by the third stop, I just barely got it to crank. I got home and parked it.

....tonight, I got in, and it fired right up!!!!! Now to be fair, I put a multimeter on it when I got it home and it showed it at about 5 volts, HOWEVER....astonished that it magically charged itself in the garage over the last few days, I was able to determine that multimeter was bad. DOH! ....so....I can't rule out that on the way home the other day, it did in fact charge. With a new MM, it was at 14.5 running, and 12.7 when I shut it down. ...but of course, no symptoms of a problem either. I'm gonna keep the MM in car.

So thoughts?
I'm thinking it's not a short or a drain somewhere, because 99% of the time it's fine, and I go 2 or 3 weeks sometimes with no driving, and it cranks right up.
I'm also thinking the battery is OK, because from what I've heard, it's either good or bad. Not back and forth.

...any thoughts or ideas? Things to check?

 

check all your ground conections

 

things to check. ground to bat and pos to bat (given)
check the one wire that bolts onto the alt (not plug in) and make sure its tight (was loose on a truck of mine got the same issue due to random connections which allso caused weak starts with good battery) and have alt tested sometimes the regulator inside them can give u some hea dach

good luck

 

Thanks guys. I'll go through everything.....

 

Another trick... if you have a deeply discharged battery, sometimes the charger can't even charge it... in that case, hook up another good battery (like you're jumping it) and also the charger and that usually revives it...

Rafael