Do these alternators go intermittent when they're bad?
My 2003 4.2L TB is on the original alternator, nearly 200k. No funny noises, and RPMs don't seem to matter. The other day the voltage went to 12 (and a bit lower) while driving. Took it home and waited a couple days. Magically it fixed itself and was back to 14V....for a while, then back to 12V. That happened again today, started at 14V, drove 30 minutes and then it went back to 12V.
My 2003 4.2L TB is on the original alternator, nearly 200k. No funny noises, and RPMs don't seem to matter. The other day the voltage went to 12 (and a bit lower) while driving. Took it home and waited a couple days. Magically it fixed itself and was back to 14V....for a while, then back to 12V. That happened again today, started at 14V, drove 30 minutes and then it went back to 12V.