Hi er, I mean HELP!
86 toyota pickup 22R
Charge and Brake light suddenly came on last week.
Wasn't worried too much because the (other) 86 I had a few years ago did the same thing with a loose connector to the alternater. But I was driving in the rain and the wipers seemed slow so I took it home. The next day it was hard starting.
So here's what did, see? I took the alternater out of the '93, swapped the plug end and sure enough, the lights were still on!! (ggrrrrrr)
The voltage at the battery while it's running does show 14.34 volts so it IS charging, I cleaned up the battery terminals all nice, nice and checked the white wire all the back to "you know where". A test light also indicated that I had continuity through the alternater.
HHmmmm, I wonder what's going on.

Most likely is the alternator brushes are near the end of their lifetime. See this article for the cheap fix;
Alternator Brush Replacement

If you still have the stock alternator, its highly recommended to just replace the brushes on the one you have and not get a cheap auto store rebuild (which are typically way lower quality than the Toyota factory one)

I had this happen on my '85 did you check for the battery cables maybe loose or worn out if that's not it I would say get a new alternato <img src="/forums/images/graemlins/kewl.gif" alt="" />r

My 86 did the same thing, but the voltage was very high at the battery. I replaced the brushes and the voltage regulator while I had the alternator off, works as good as new now. $20 something for the brushes from the dealer, and $65 for the regulator from NAPA.

I know!!! I know!!!

Happened to me. Here's an old thread for you to check:

Ohmic Loss

I grabbed the new brushes from the dealer. Reinstalled the alt. and now the charge and brake lights dim every three or four seconds. The trucks been off the road for several days and was really slow starting this morning. I don't have the time or money to deal with this.
Oh, this weekend I had the 86 alt tested (the one in the truck now is from a 93 with a swapped plug) at the auto store, it tested no good so I traded it in for a rebuilt. So now I need to swap the plugs back and try again.

problem solved, I put in the rebuilt alt from the parts store and the lights went out. So it seems I had two bad alternaters.