Voltmeter Light Question

[ADVFJ80]

Hi everyone,
Let me start by saying I haven't post in a while. I sold my FJ60 two years ago, and have regretted it ever since!

Fast forward, I bought a '97 FZJ80 a couple months back that I daily drive, and life is grand. I'll put up a rig post, but for now I'm looking for some assistance.

Recently, the voltmeter Light comes on when I start the truck. It stays on for several minutes, then intermittently goes off and on. Doesn't really seem to have any consistency. The charge system passed a test, but the battery didn't. So, one AGM battery later, and the issue persists. Voltage as measured by the scan gauge reads 13.5-14.2, and I've seen as high as 14.6. Again, no real consistency.

I'm assuming it's the alternator, and also assuming it's internally regulated? Any other ideas of things to check? I'm going to check the alternator ground tomorrow, but thought I'd throw this post out to see if anyone has had a similar issue.

Thanks in advance, cheers!
Randy

 

[Rusty Marlin]

It's interesting that the voltage is fluctuating, mine runs steady 14.6.
That leads me to think the voltage regulator is kaput, not the alternator itself.
Nope, low voltage is the generator.

 

[Kernal]

As listed in the FSM pages agove, check that the alternator belts are tight, not slipping, and that the battery connections/cables and fusible links are in good condition.

 

[ADVFJ80]

This is very helpful, thank you both. I'll look into it!

 

[ADVFJ80]

It's interesting that the voltage is fluctuating, mine runs steady 14.6.
That leads me to think the voltage regulator is kaput, not the alternator itself.
Nope, low voltage is the generator.
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Thanks so much for this! I followed these FSM pages, and everything tested fine. Literally the last thing I checked was the nut on the positive battery stud. It was a bit corroded, and also just a teeny bit loose. Quick clean and a proper tighten, everything seems to be fine now.

Thanks for the help, all the same.
Randy