1jz Alternator charging problems, I need the experts

[AF1JZ]

So, I'm thinking my alternator might be going bad and I wanted to confirm with you guys. I was driving home from dinner last night and all the lights got dim and radio was turning on and off then it started sputtering. The car wouldn't go any further so I pulled over. It was dead. I got a jump after looking at all my wires to make sure they were still in tact. After the jump it drove fine all the way home no problems.

I go to work and it starts just fine to work. Then I leave to go home for lunch and it does the same exact thing as last night. So, I leave it at a parking lot on base. I just went and jumped it again and it was fine and drove home.

So, I put a multimeter to it and it starts at like 12.40 volts and slowly creeps it's way down to 11.70 volts in about 10 mins.

Does that sound like an alternator problem? Thanks for taking the time to look.

 

[OneJSupra]

Take it to Autozone, they can test it for you free or try this ...

http://www3.telus.net/chemelec/Projects/Alternator/Alternator.htm

 

[AF1JZ]

I think I got my answer in one the diagnosic sections.

4) check the battery Voltage.
*** The Battery voltage Should read between about 13.8 to 14.2 volts. (Possibly up to 14.5 Volts.)

Mine was low 12 volts- high 11 volts


PS- sweet ride you have.

 

[supradaddy0803]

There has been many ways to check the alternator on the car but if you check the battery while the car is running on the posts you should have like 14 volts. Then if you check the cables not the posts then you should have a match on the voltage. Sorry I install telecom batteries for a liveing no 12 volt battery charges at 12 volts. But anyways a easy check to see if your alternator is good take the belt off of it and spin it if it spins free and keeps spinning for a while then your brushes are bad and that would explain your charging problem. But then there is the voltage regulator and if it is bad then autozone can check it for free.

 

[namkiii]

also theres a little wire that gos to you battery for like body power check to see if its lose

 

[p5150]

You could also be having some other problems. Ensure that the entire length of wire from the alternator to the #2 block is in good condition and not corroded or broken. Ensure your ground wire is not corroded or broken and that the chassis is well connected to the block with a decent sized ground wire.

I would say that the sudden onset of your problem indicates a faulty alternator, but if you have other small things contributing to the problem then it is likely that you could milk a few thousand more miles out of it if you take care of them.

Once upon a time I had an alternator charging problem on the 7M, and it was due to the wiring gauge being too thin and long once I transferred the alt to where it is on the 2j to make room for my FFI. Usually alternators dont just crap out, they fade out. The other things that may be wrong exacerbate the problem.

I used to get the parts at ABC by Wal-Mart on route 38 just off of the 295 exit. They usually come with a lifetime warranty and are the least expensive but YMMV.