Toyota: Battery and brake lights on, toyota 4x4 pickup, bad computer

Question
I have a 1989 toyota 4x4 pickup. The battery light and brake light keep coming on. The truck runs fine. I had a local autoparts dealer check it and was told the alternator is putting out 30 amps instead of the normal 60. He said that due to the fact that the brake light is coming on also, the computer could be going out. Help!

Answer
The autoparts dealer is clueless.
You do NOT have a bad computer.
You do, however, have a bad alternator.
The alternator internals are designed to illuminate BOTH lights on the dash (brake and alt) when the voltage regulator or something else fails. Replace the alternator, and your troubles will be over.