2nd Gen 3VZ: Checklist before doing alternator?

[itgogitrev]

Hey guys, I believe I have another fried alternator. I've done the following procedures hoping that there was a cheaper fix than getting a new alt:

- Replaced weak (and half broken) battery-to-fender ground with 4G cable
- Had battery tested, tested fine
- Replaced ALT 80A fusible link since original one looked warped but not broken

Is there anything else to consider before I replace the alternator again?

 

[flyinhawaiian01]

4awg from alternator to battery positive terminal would be another thing to do, but if you've fried that many alternators, something's going on here!

You either have some sort of short that's frying the regulator, or your battery is toast and the alternator's having to work overtime as its aimlessly keeps forcing amperage back into that battery.

Do you have some sort of really high current equipment you run a lot in the vehicle while the engine is running? Winch? Car audio with HUGE amps (like a few thousand + watts)? Linear amp for a radio pulling more than 100A? Lots of lights?

 

[RAD4Runner]

Is there anything else to consider before I replace the alternator again?

Yes, get a multi-meter and take some voltage measurements to confirm things are really bad before replacing them, so you can be certain that after replacing the bad part your problem would be solved. Blindly replacing things will cost you money and give you no idea what really caused the problem.

 

[penbergm]

Alternator from autozone has free lifetime replacement. I did that for mnay years before upgrading to a 120A Jaguar alternator in my 1st gen. Do you have oil or power steering leaking on you alternator?

 

[itgogitrev]

You either have some sort of short that's frying the regulator, or your battery is toast and the alternator's having to work overtime as its aimlessly keeps forcing amperage back into that battery.

I had the battery tested and it's good. I can run the engine off the battery with the alternator disconnected for a good 2 minutes before voltage starts dropping.

Do you have some sort of really high current equipment you run a lot in the vehicle while the engine is running?

Nope, just an aftermarket headunit. No amps, lights, or winches... yet.

4awg from alternator to battery positive terminal would be another thing to do.

Cool, I'll look into that.

Do you have oil or power steering leaking on you alternator?

Not anymore. I had a front crank seal let go on me and basically cover the front of the engine in oil. I replaced the first alternator after I fixed the seal, but I went back and cleaned up the engine bay after the new one was installed. It's likely that some residual oil could've gotten in there.

get a multi-meter and take some voltage measurements to confirm things are really bad before replacing them, so you can be certain that after replacing the bad part your problem would be solved.

That'll be the next course of action. So far, the attempted fixes have been free (parts were already in the garage and I'm chalking them up to maintenance). Just ran out of time this weekend.

 

[itgogitrev]

Follow-up report

I ended up testing the alternator and it was done. I think a combination of the oil spray from the leaky front main seal and the bad ground killed this one.

Swapped it out today in about an hour and runs like a top. Hoping that the new wires help keep this one alive.