jamielee

'88 4runner - installed a new alternator and have had to jump my truck every day - any ideas on what could be draining the battery? The battery is about 6 months old. Nothing else has been done, nothing else has been hooked up or left on overnight etc...

swampfox

It may be a bad alt. You might charge the battery and unhook all the wires from the alt and let it set over night . If is dead in the mourning it is in the truck if not it is in the alt.
You will need to cover the wires at the alt to prevent any shorts. If it goes dead with the alt unhooked the battery could also be going bad .Most part stores can do a load test on it for free.

jamielee

I'll try that, thanks! Hopefully it's just a bad alt and nothing else...

peckinpah

I know they're a PITA to remove and reinstall, but I would get it tested at Autozone or Cragen.

jamielee

yeah, it sure was annoying trying to get the old alt outta there. ended up having to take the bolts off the fan shroud to move it out of the way. it was still like some sort of impossible puzzle, twisting it and turning it until it was free...

thanks boys! gonna unplug it tonight and if the battery's still good tomorrow i'll get the alt tested...

BigBluePile

iTrader: (3)

Why not get a volt meter and see what the battery is reading?

jamielee

couldn't I run it down to Les Schwab and have them do it? i should just have them charge it up!

BigBluePile

iTrader: (3)

Yes. Yes you could.

bennyt4130

I'm certainly no expert but I would have the battery and alt tested. Chances are the alt is good but batt won't hold a charge. I am assuming that the battery ran down a few times before the alt was changed? That is what kills batteries from my experience. Good luck.

wyoming9

iTrader: (1)

By chance when you replaced the alternator was the battery brought up to full charge?? Before starting the truck.

At anytime since the change does your low charge light come on or if you have a voltmeter what does it read

You did remove the ground while changing things. These trucks had poor grounds from new that might be part of your problem.

This was a known problem on Fords the discharged battery would cause the alternator to have full output and fry the diodes .

Another the thing the wire coming off the B terminal of the alternator gets brittle with age and might have broke or got to the point it no longer conducts

If you want to work on these trucks a Multimeter is a must even a cheaper one will help you to test and know all kinds of things

Good luck