My battery is not charging itself properly.. Here are the things I have already done: Started off basic by checking terminals for looseness/corosion and replaced them just to be sure, then reground the negative to rule that out. I removed the battery and alternator and took them to Autozone and had them tested, both tested GOOD. I also checked fuses in the engine bay and no problems there. I have since taken a voltage meter and checked voltage of the battery, it gets around 12.7 while sitting and around 14 SOMETIMES while the car is running. Due to that reason I believe the alternator is working but just part of the time. Could there be a loose wire or short somewhere? Could the alternator or volt reg inside the alternator be bad but was missed by autozone? Im running out of ideas here, if anyone has some electrical background or insight I would greatly appreciate it. Thanks!

 

you should be able to check if your alternator is working with the voltage meter.

 

Instructions on how to do so?

 

I did it a few years ago with my dad, we just started the car then held it on the positive and negative(or ground maybe) terminals on the alternator.
Does anyone else on here know if i am correct?

 

well it does sound like you would be right on this one

 

Ok, heres an update: I have not tested the alternator myself but I HAVE noticed one thing. The parking brake light stays on but it shouldn't, the brake is not engaged in any way. I had the voltage meter hooked up to the battery at one point and noticed the brake light go off, when this happened the alternator kicked in and the battery charge went up to 13.6 or so. When the light is on it will not charge, when it's not on it charges properly. Does this mean a short somewhere? A bad relay? None of the relays in the small box looked bad though..

 

The brake light will come on with the charge light when the alternator isn't charging with the engine running. There are several threads on this topic here somewhere. I have been having the same problem with intermittent charging from the alt. and the two lights coming on. I replaced the alternator with a Toyota remanufactured one ordered from Toyota of Dallas. I also replaced the original-looking negative battery cable due to corrosion and fraying of the cable. (I've had the truck for a year now and finally got to it.)

All seems to be working normally now. I'd suggest you replace the alternator, or borrow one from someone to test and see if your alternator is the problem.

 

CHECK THE BRUSH'S
$9.00 fix if you replace them it will save you from buying a new alternator , check 4crawler.com he has a nice wright up about it and I believe you can get the brush's from his site.

 

Ok, havent had time to dig into it again but I will get new brushes and try that.

 

i was in the same boat...alt. tested good...checked everything else..nothings wrong...replaced the alt. with a new one from Oreiley's..and everything is fine so far...

except for my ignition module and coil going out..

 

I wish I'd read more about this before ordering and installing an alternator. But at least now I have a good Toyota remanufactured unit to work with if it ever gives me trouble again.

 

Now you say you changed the battery terminals . Did you crimp new ones on??

I have found that these vehicles come with very poor ground systems and over time they degrade even more . A alternator or starter that works on the bench but is a few years old might not work in the vehicle . Where a new or rebuilt unit being fresh will work for a period of time could be weeks months or years

When I get a new Toyota to me first fix is always to upgrade the battery terminals and cables . I use the cut off ends of number one welding cable cables damaged by something dropped or burnt like 5' or 6' from the end and Deka marine battery terminals .

This has fixed a number of charging and starting issues

 

Well, changed the brushes in the alternator (3.99 from Napa) and all is well so far.... *fingers crossed*. If it dies again I will be back on here hah.

And as for the terminals being changed, the negative one came with a little metal bracket that tightens the two neg wires together. It seems to be holding fine.

 

sometimes the forks in the alternator get dirty too causing the current to not flow when it passes around the coil. May be why the new alternators are fixing it.