UGH! Batteries / Alternator GRIEF!

[clatteringcanuck]

Hey all...

Okay, here's one for ya. 2005 SD FX4 CC SB. Motor, exhaust EVERYTHING is stock (other than the DR4.5" lift and 35" Yoko's.

Here's the problem. Two weekends ago I was towing my fifth wheel. About 60 miles from home, 2 miles form the campground the trucks gauges, power windows, climate contrl bit it. Truck was still running but I KNEW the alternator was toast.
Made it to the campground and yeah, alternator was fried. I checked it and it's a 110A unit, too small for towing. Ended up having AAA come and tow the truck and trailer back home (Thankfully no charge, THANKS AAA)!
Replaced the alternator with a stock 110A unit again as it was on warranty. This is the THIRD alternator I have replaced in the last year.
I also replaced the batteries this past spring so I know they are okay.

Anyway, replaced the alternator as I said, let the batteries charge and all was happy times. Drove the truck around for a while, seemed pretty cool.

Went out yesterday, tried to start it after sitting 24 hours.... battieries were low as once the GP's were warmed it didn't have enough juice in the batteries to turn it over.

Now, I am guessing I may have fried diodes in this new alternator ONCE again. Then again it could be the batteries. After boosting I had a friend bring over his code reader... nadda. Everything is cool.

But!!! Why does it keep killing the alternators?


I'm starting to get just a bit frustrated now.

[clatteringcanuck]

Sorry, just to add info...

I did have the electrical (7 pin) setup installed int eh box of the truck AND a brake contrller int he cab as well. All of my alternator trouble started after this install.

Do you think that there may be an open ground somewhere or something that is killing the alternator? I mean really, when NOT towing the system should be 100% fine.

I'm going to boost the the truck and meter the POS out tonight after work.