Hey all,
Used the forum for a while but just now registered, alas all my searches couldn't provide a solution so I felt I needed to man up and ask the experts.

For starters, I have a 1990 4Runner with 22re out of a 95.

About 6 months ago my T4R started dying on me occasionally, always at night when I kicked on the Hi-Beams. First thought was alternator, so I replaced that, and the truck seemed to do better for a few days, but then it happened again. Also, it happens sometimes durng the day, with no headlights on and me running minimal electronics. Unfortunately due to work/traveling I havent had a lot of time, and electrical systems on cars aren't my strong suit. In the past 6 months I have been through 5 alternators, replaced the alternator belt, and a new battery. Also, after I took out the last alternator I took it in to a parts store and had em test it, they said it was in perfect shape (wish i woulda thought to do that earlier on but oh well).

The new alt i'm running is a 70 amp, and when its running the battery is reading 14.7V (off its around 12.7V), but it still dies on me when I run too many electronics. Also, the last time I had it checked they said the battery was only getting about 35 amps, even though the voltage was that high. I can deal without the radio, and even the AC despite the 105 temperatures we got down here), but at night the hi beams come in pretty handy.

If anyone has any possible solutions or other things I should check it would be a huge help. Gonna do a complete frame off on the truck when I get time but until then I just need somethin that i can count on to get me there.

Sounds like you have a bad positive connection somewhere, and when you're hitting the hi-beams the alternator can't keep up... have you checked the batter/chassis ground? If that is loose, it will cause all kinds of **** to go haywire

ya mean where the positive terminal is grounded to the frame? Sorry my electrical knowledge isn't all that spectacular. If so I did check that, it was tight but grimy so that was one of the points I cleaned.

gosh that sounds like a bad ground somewhere

Thats what I was beginning to think but I didnt know where else to look. I remember reading way back when a post that had a lot of the correct voltage readings between different points in the system, but when I tried to find again I couldn't. I know how to read a multimeter, I just dont know what all the readings are supposed to be so if someone does remember that post or can give me some starting points I would really appreciate it