Dead Batteries When Using Bunk Heater

As the title says, the auto start stop on my 2019 T680 isn't working with the bunk heater. The 3 times I've tried using it, I've woken up to dead batteries and the truck trying to crank with ~8V. I'd there a setting I'm missing or is this a dealer issue? It starts fine when I'm running the fan, though, so idk what to do from there :/

 

Once your batteries starve below 8 v there is insufficient ability to boot and keep electronics active long enough to do anything at all with dying rig. You need to have about 12.4ish volts to maintain everything in order long enough to finish a typical crank and startup of a heavy truck engine. Anything less than 10 is a bricked rig.

Keep pulling on them poor batteries and eventualy you will zero them out totally dead in the worst of winter storms stranding you and trying to pull your body to enough exposure to the cold to kill you too.

 

The thing is, I've got my auto start turned on. It's just waiting until my batteries are too low when I have the bunk heater on. It starts just fine when I have the bunk climate set to "cool," but cuts off immediately after switching it to "heat." My International LT would auto start with the bunk heater running, so logic says that this one should too unless it's some Paccar shenanigans that I don't understand

 

Read owners manual, if you’re not missing anything then call the dealer.

 

Yogi key no start cold is.

Did I even type that right? Star Wars is a concept I remember but Yogi as a trucker would have issues with a truck that refuses to run properly heating or cooling in addition to having to kick over and fire itself up to feed batteries that are falling below say 12.4 volts.

You would think a APU will provide hotel support to you in that sleeper heating and cooling as well as feeding batteries. *(And keeping the main engine block coolant relatively warm as well as some heating into the fuel tank returns against winter etc.

 

Sounds like whatever sensor that tells it to start is kaput. Go by a dealer and see what they say.

 

In my 2018 389 if my bunk heater was on and batteries got low it would shut everything off to save enough battery to start the truck,"low voltage disconnect " I have 4 batteries and they lasted 197,000 miles, threw 4 new CAT Batteries in, runs all night without shutting off now. Maybe need new batteries?

 

When running the fan or ac the generator in mine is always running. If you are running just the heat, the generator only runs occasionally.

If you have a setting just for charging, does the generator turn on?

Dont know how your system is set up but it sounds like your low voltage detection is not hooked up. Could be a wire or a setting.

 

In my opinion you have an issue with the heater drawing way too much amperage and draining your battery prematurely. I usually can run my bunk heater all night long with the truck off and still have plenty of juice to start it up in the morning and my batteries are over two years old.

 

Everybody saying run to the dealership phone the dealer they don't know #### these blogs are supposed to be about people who know what the problem is dealerships are a waste of time and if you have a week to 10 days to wait around for them to find you a spot to get in you'll spend another 2 days there and they won't know what the problem is