Troubleshooting Truck electrical

[Eric H]

Why not just install the rebuilt alternator you already bought?

Depending on the year the charging voltage may be controlled by the PCM.

It may be keeping the voltage low so the amperage doesn't get too high pushing against a low battery..

[maxhifi]

Originally Posted by Eric H

Why not just install the rebuilt alternator you already bought?

Depending on the year the charging voltage may be controlled by the PCM.

It may be keeping the voltage low so the amperage doesn't get too high pushing against a low battery..

I think will do just that. On the way to work today the "charge" light came on a few times when I was stuck in traffic. I had to rev it up to get it to extinguish. The reason I installed just the regulator, is the alternator has an oil lubricated vacuum pump mounted on the back of it for the brakes. I didn't have enough time that evening to do the whole job, so just at first tried the regulator to try and get it going.

The truck is very simple, there's no computer or external electronics, the regulator is just a little steel can which Toyota refers to as an "IC Regulator" and is attached to the brush holder under a little metal cover.