alternator has been pulled and tested good, battery has been pulled and tested good, 80amp alt fuse has been checked good, no obvious/visable wire damage(advice on good places to check more thoroughly?)

its my buddys truck(93 22re pickup base 5spd), he had been driving for a couple hours straight when the CEL and brake light came on. after that the guages started to dim and the engine began bogging down, then the guages quit and shortly afterward the truck died.

this was about 2 in the morning so i went to get him and looked under the hood figuring it was the alternator, and i mistakenly thought his belt was gone (it wasnt, he just only has 1 belt) so we left for the night

so the next day we go back out to it, i look again, dont see anything wrong, check wires and the fuse, and ask him to turn the key. starts up fine. not ready to call it good, we wait for it to warm up. its cool here so maybe 10-15 minutes later it starts getting warm and starts the death cycle again. so i figure maybe the alt is dead. we take it to autozone and they say its fine on their little 3 point check. pull the battery, it checks out fine as well.

ive been out of the automotive mindset for a good bit, and could really use some help troubleshooting this. please talk to me before i lose my mind.

thanks

 

Test the amperage the alternator and batt.is putting out with the truck running and lights on as if he was re creating the conditions that night.Could be a bad ground or short.

 

I'm not too electrical savvy but maybe someone here can tell us what they should be putting out.i thinks batt should be about 12-14 amps help please guys.

 

I have had several alt tested at autozone there test are iffy at best in my opinion so it runs when cold gets hot and acts up sounds like a alternator is building heat possibly internal failure once it gets hot internally it starts to act up may not be converting ac to dc power once hot .it was cold when u took it to autozone wasn't it ? Gauges possibly stopped working do to voltage drops or a non AC current leaking into the system

 

ya, sounds funny. test the battery when running with alt on vehicle. if charging more than 13v u should be good. -if u let it run n it dies, test the battery immediately -if low voltage than cud be the alt.

also, (from left field) could be the fuel pump cutting out (seen a few of this) - when running, n gets hot, it could be cutting fuel. also check the fuel relay /efi relay. the heat/warming up may have an affect on this also.

 

well after taking the alt out and putting it back in (with a new belt) its running fine.

for people with future problems(or me if it acts up again):
the last belt that was on was too small and required that the adjustment slider be all the way towards the engine (and i think it was still too tight even then)
im -hoping- that it was just a belt slip problem caused by the above, but when i ran the tests the first time(and we found that the battery was not being charged) i didnt notice any slippage.
inspection after the fact showed some possible damage to the sides of the belt as well as a change in the surface texture(looked sorta like tar instead of the regular belt rubber stuff)
my buddy said he would hear strange sounds that may have been slipping when i reported my results back to him (hes currently in vegas with my tacoma). seems odd to me but if this works it works. :knock on wood:

durring the process i did also move all the wires around and unplug/check/re-plug things. if this was an electrical issue it may have helped without controlled results.

thanks everyone for your input and help