New batteries, still not enough juice to run fridge over night?

You have a high draw of amps, running a heater takes a lot of power. You need a power source that will keep up with the your needs, Shore power, generator APU batteries alone will not do this, in the cold batteries will drain faster.

 

The voltage is fine, even before. Cranking slow could be a wiring issue too. I'm actually surprised you see 12.8v after running a bunk heater all night. Maybe your voltage gauge is goofy. I'd expect 12.0-12.4 to be the norm, depending on temp.

 

Get an apu..

 

I have a 2012, had the same issues but it was the fridge. I went through 3 of them before I got one that worked properly. They changed the wiring on the back of the fridge for that stupid LVD module, after the truck shut off it wouldn't allow enough power to run the compressor, only the fan. Everything in the fridge would be defrosted and warm by morning. I've got a thread on this in the forum. By the way I can run the fridge and bunk heater all nite on these batteries with the voltage dropping from 12.8 when you shut the truck off to 12.2 by morning, and this was the 3rd winter on these batteries. I've got the inverter/charger and make sure I plug into shore power when I'm home to keep them peaked.

 

You said you saw 14.1V with the truck running. Them other readings are they with the truck running or just the key on? Because they are normal too with the with the truck off. Running it should jump right back to 14.1V or you have alternator issues.

If you are reading better than let's say 11.5V (truck off) in the morning and your fridge is warm then the problem lies in your fridge. Your truck has a built in low voltage shutdown. If that hasn't kicked I'd say yeah it's the fridge.

 

Well as Cruiser asked, does everything charge back up when you start it? It seems that if you've gone through 2 sets of batteries on a 2013 truck, one would assume that it's more than a coincidence that 2 sets of different batteries would be bad. IMO.

 

The thing is the fridge shouldn't be warm with them voltages. I'm thinking something along the lines maybe it's freezing up or not performing up to par from low freon or what have you. It's running longer trying to cool down would explain the increased draw. Maybe it has a defective compressor. If you are losing your food then turn it off for a day and see how the batteries perform with just the bunk heater.

My dorm fridge use to take 150 watts to start and cruised on 70 watts. It maybe ran 5 minutes every half hour. They don't use much. If yours isn't working correctly it's probably running continuously and would explain the increased usage of your batteries.

 

They also put out a service bulletin for a fix that would work on some fridges. If you pull the fridge out and look on the wired control module you will see a wire on the "P" terminal.Pull it off and tie it away, it was an extra connection they put on for that stinkin' LVD crap. This will eliminate the compressor shutting off when the truck's not running and it should run normal. Ask your dealer to look at FSB ( Field Service Bulletin ) 885-007 Refrigerator Inoperative. As I said, I went through 3 of them.