anyone able to help 5th alternator in e months

Internationals have a main cab feed stud on the firewall that feeds the fuse panel. They get corroded and loose voltage going into the cab. This causes high amp draw when running normal low load accessories which in turn makes the alternator work overtime without much of a break. The alternator overheats from extended charging time. Cleaning up the cab feed often takes care of the problem.

 

You have a gremlin somewhere. Do a continuity test. I dont think batteries would do this. What exactly is going out in the alternator? They dont just fry out like that. You more than likely have a hot short somewhere and your volt reg is burning out. Look for melted wiring or loose cables. Or both. Lucky you havent had a fire.....yet.

 

Did you change anything right before the first failure? Maybe added a battery powered APU, or added some batteries because your inverter was draining the ones you had during your downtime? If you're draining your batteries while you sleep, it's possible that the charging needs of the batteries exceed the alternator capacity when you start up.

 

if you take a volt meter and measure between each cell, (cell test) you can see if there is a short anywhere in the battery that would be causing a high draw.

Just need to pop the caps off with a screw driver.

It's best to use a hydrometer, but you can test with a voltmeter too for a shorted cell.

you should see 2.1 volts between cells. With 6 cells, that would give you 12.6 volts over all in a good battery for a full charge.

 

check your ground cables, battery to frame, frame to body, battery to engine block, add a ground strap from your engine block to your alt gnd post.

Make sure the paint is removed and clean metal is exposed at every connection. make sure there is not any corrision inside the connectors that terminate the ground wires or straps.

Grounds cause a multitude of problems but are drequently over looked. Dont mess with the batteries, when you change the alt, change the batteries. They nned to be of the same quality, 1 bad battery will take them all out.

 

Sounds like short to ground to me. Usually if an alternator packs it in you drop down to 8 volts then shut down. Make sure all the battery cables are not rubbing.

You may even have an open. If you have a breaded steal ground strap, replace it. Or at least next time the voltage drops, put a jumper cable from the altenTor ground to the battery ground. If voltage goes back up, it's the ground strap.

 

My first thought would be to check the connector plugs going into the cab for corrosion. That would explain the voltage drop. Aloo check your grounds making sure all of them are good. If the frame to battery ground is good and the engine to frame isnt all of the current may be backfeeding thru the alternator.