3 light warning

[photogod]

So i get the 91 out of storage today drop in the freshly charged battery and drive her home, 3.5 hrs, and when I get home and park it and let it idle, the AT Oil light, the light above the voltmeter and the e brake light come on and stay on. I reved it and they dimmed and went out but came on when the engine went back to idle. The alt is charging at 14 or so and it doesn't change from idle to 2000 rpm. I'm thinking alternator. Any ideas from the pro wrenchers out there? Thanks.

 

[psfpilot]

Similar story, same result here. Our 92 had a wounded alternator after a new battery was erroneously installed backwards. The three lights you describe were illuminated. We took it to O'Reilly's and had it tested. It was charging at about 1/3 rated output, and couldn't keep up with the demand of starting, blower, and lights. The parts manager said something about blown diodes being the cause of the 1/3 output, so I suppose that if one could find the parts, one could follow the FSM instructions to rebuild the alternator.

 

[landtank]

If you had even a single diode out you would not get the 14v you are seeing. I'd first check the brushes for that unit. They are probably replaceable and I've done this several times on different Toyotas and had it work everytime.

 

[Razorshock]

Just had to replace my alternator, same exact readouts (little to no charging, cannot keep up with headlights) with a load tester. Ordered reman from CDan. Cdan told me there were two different types, and for the type that I had replacing brushes was either not an option or exceeded the cost of the reman alternator.

 

[psfpilot]

If it is the brushes, wouldn't that be indicated by a gradual deterioration of the charging capability, rather than sudden failure after the insertion of a new battery? Also, is it pure chance that both photogod and myself had the same sudden indications of charging system failure after replacing the battery?

I'm curious, because I don't understand much about the alternator system's construction and therefore don't have much understanding of precisely what would be the likely culprit in these two malfunctions.

 

[photogod]

The battery was out of the truck all winter and kept in a warm greenhouse and I did reconnect it properly after an all night trickle charge.