Alternator Over Charging (yes, another one of these threads!)

[ilovemyblazer]

I'm having an over charging problem on my M1008. The voltage meter will spike way up while I'm driving, then come down to normal for a few seconds, then back up. I was just going to let it go but it blew out my headlight now so I'm here for help.

Out of all the threads I read the answer was to either 1) Rebuild alternators. 2) New batteries. 3) Check connections.
I've done all.

First Gen 1 stopped charging, so I rebuilt it (cucvelectric complete kit). Worked great for about 3 days then the overcharging happened. I knew I needed new batteries for the cold weather coming so I got some nice ones which set me back about $240. Got those in there and still over charging. Ordered another rebuild kit and did gen 2. I could tell the voltage regulator was bad in it so I got excited thinking this was my problem. But of course it wasn't.

So to sum it up, I have such a bad over charging problem that it actually blew out my head light. Gen 1 & 2 are already completely rebuilt, new batteries, all connections seem to be fine.

Any help is greatly appreciated!

 

[Warthog]

Tale your alternators to a shop to have them looked at. Sometimes parts are bad from the factory. Just because it is rebuilt doesn't mean it's good.

 

[Barrman]

You need to narrow down which alternator is the problem. Put a volt meter across the terminals of a battery and then across both terminals of the other battery. 14.4 volts is what each battery should show with the engine running. If they are both there, hold the engine at a higher rpm and see if one of them starts jumping around.

I suspect you are going to find a corroded connection of bad ground somewhere. I know, you checked all your connections. Did you check your driver side alternator ground too?