1990 3.0 3vz, its overcharging at the alternator, but losing voltage from alt to the battery. I've got a voltage drop between the 2, but unable to locate it. Alt is new, battery is only 2 yrs old. I'm suspecting the connection from the alt at the battery wire near the starter maybe corroded. Does anyone have any pics of the alt/batt/stater cable? All the grounds are good,clean and tight. Occasionaly the truck just dies, engine and all interior/exterior lights, clock resets, there is no power to anything, sometimes it spudders and continues to run, I've checked the usual problems, cables at the battery are clean, etc. Any help would be appreciated.

 

So you only have 2 sources for electrical power... the battery and the alternator.
the truck will run without one or the other, not long on just the battery, but not at all without both.
so your " black out" sounds like your losing both for some reason which i would guess to be fairly detectable...
It's not just a little short somewhere...
Don't know if this is helpful at all, but good luck.

 

Check for corrosion or wire almost broken. More likely corrosion if eating volts. battery cables, or the 10 gauge wire that goes from alternator to battery +.Check at the fusible link near the battery. Usually about 3" up the harness from the battery terminal clamp.

 

Update: what I found was to much corrosion built up on the wire from alt to fusible link, found a voltage drop between the two of them, of course you have to pull the fuse box up and the link out from the bottom to see anything, thanks for all the advice, feel free to pass this info along to anyone who maybe having similar problems.

 

When I had an intermittent "black out" issue last year sometime, it ended up being the fusible link connection onto the battery terminal. I left my key in the ignition, with the door open, and just starting wiggling wires until I got to the fusible link wire and it triggered my "left key in ign" buzzer. That's how I tracked it down.

 

Thanks for posting your solutions