Batteries go dead in about 3 days, there's a short somewhere.

Ya and I didn’t know wtf was happening! Worse than eggs. When they looked at the batteries they were bloated and wet with smelly acid. I had the same symptoms the OP did before the smell.

 

I had a guy get pissy with me for not changing his batteries while they were gassing. Good chance of it exploding right in your face when you take the cables off.

"Um no I'm not touching that until its done gassing. See you after lunch!"

 

Don’t worry, OP. Your batteries might not explode.

 

Ya...one or more batteries is Toast (dead cell). I can leave phone charging for 5 to 7 days and still starts.I mean you probably have 4 800 amp batteries? Id have all batteries "load tested" for free at Autozone.

 

When I had my sat. radio running all the time it would run down my good batt. in 3 or 4 days I put it on a switch that shut it off when key was off and it could sit for a wk or 2 and start up with no prob.

 

is it your truck?

If it isn't then ... just so you know maybe he has a bad ground because it sounds like he needs to start with a real check of the batteries then go from there.

A good tech can see what's what in about 10 minutes with the right stuff, don't need to second guess with some parts changer.

 

I turn off power switch at the end of every shift. Weekends most importantly because we found 3 days would kill the batteries enough that the Cascadia would not start. I'm surprised the gremlins can draw down the battery so quick.
Not my truck, not my problem

 

Start pullin fuses till the draw goes away. Load test the batteries as well.

Start simple and go from there.

Or dont let the truck sit not running for 3 days.

 

You should be able to tell with a multimeter which circuit is draining you batteries.

 

For those of you with an APU, if your APU kicks on within one hour after a long drive and shutting off the engine, there is a problem with your batteries. The exception, of course, is if you are running a microwave or anything of that sort.