anyone able to help 5th alternator in e months

What size alternator are you using and what capacity batteries do you have? Does you truck have any kind of low voltage protection? What does your voltage show when the truck is running?

 

13 to 13.5 OS to low should be running 14.5 are the altanators rebuilt? I would check all the connections and grounds have you checked the output at the altanator?

 

Cell test your batteries.

That's low voltage. Why?

 

for your voltage to be that low, you either have had a slew of bad alternators, or the wiring connections to the alternator have a problem, or you have a humdinger of a dead short someplace else. At the very minimum you should have 13.8 when running, or more likely 14.2.

 

Check for voltage drop going into cab with a voltmeter.

 

Id rewire everything if I was you. Sometimes when testers test with pin pricks going thru insulation, it causes all kinds of problems from moisture corrosion, etc.