I have a 99 PSD and it ended up being my positive cable had bad connections in the terminals. Luckily someone I knew knows how to replace the heavy duty terminals.

 

I'll take a look at it tomorrow! Thanks for your imput!

 

If by chance it is your battery cable, tousleyfordparts.com is the cheapest I found

 

Man, I thought you had this one whooped! No engine codes apparently. Batteries losing charge overnight. I would have to say that the alternator is still the culprit! Ground wire? I would think that if it was a module of some kind(not sure what you guys are calling with acronyms!!) but shouldn't that trip an engine code if it quit working? I have an 2002 and do not have windshield issues(thankfully!!) Try using a volt meter on the batteries and see if they are taking a charge when the motor is running. Should be around 14 volts if the alternator is working properly.

 

I'll take another look at the alternator and the wiring! This dang thing is really starting to **** me off! I love the truck, but enough is enough! Thank you for all the suggestions!

 

Had the alternator tested yesterday, it failed twice. installed the new one and took a volt reading and it was charging like it should. I also checked the amps and volts on both batteries as it was running, both were slowly climbing from 12.5v to 13.2v with amps holding at 7amps. I went out this morning and she fired right up, no hesitation.
I would have never guessed two batteries and an alternator less than 2 months olld would have been the issue! Thanks everyone for all the imput, you saved me a lot of time and head banging!

 

Check it again today and be sure it is still charging properly. Alternator should maintain 13.2 or 14.2 while running. Sounds like you have found your real problem though! Glad to help

 

Here we go again! Driving down the road and the darn thing dies for no reason! the batteries drained! Jump started it, checked the alternator connections, still putting out 13.2v ! I heard a clicking noise in the dash so I started trying to track it down and found a constant draw in the instrument cluster! Two days has past and no electrical/Starting issues. Does this make since to anyone? Help! much more of this and i'm buying a Duramax!! Lol

 

What was causing the draw on your instrument cluster? I don't understand why that would drain your batteries if your alternator was working properly. are you also running your headlights?

 

Yes, at the time it died this go round the lights were on. Guess im taking a shot in the dark! All i know is when i pulled the fuse for the instrument cluster the clicking stopped. Could be a number of things associated with the cluster. Honestly don't know where to go from here. getting frustrated.