load shedding

This is a dumb feature that causes more headaches than it is worth. Once the body controller sees 12.1 volts or less for 30 seconds it will activate. If your batteries are indeed getting weak, then you need batteries. If your batteries are in a good state of charge, 12.6 or better, then you have a voltage loss or bad connection to or at the body controller.

 

There isn't much to check there, it is feed main power by one big cable, if this was the location of a bad connection you have several electrical problems. The connections I would check would be the mega fuses at the firewall on the outside above the left tire fender, make sure the nuts are tights. The next connection is basically at the batteries, that's it. What we do sometimes is electrically bypass the load shedding relay. The relay is located right behind the center console panel that also serves as the cup holder right in front of the shifter. You will see a big relay with two big red cables each bolted on their own stud. It is this relay the body controller turns off to cut power to your accessories. All you need to do is simply remove one cable from one stud and just bolt it directly to the other stud with the other cable, so now both cables are just bolted together. If you unplug the relay from the small connector with the small wires, the body controller will detect that and throw a fault code. If you just bolt the big cables together the load shedding alarm will still go off once, the body controller will still signal the relay, but since we have bolted those cables together all your accessories will still be powered.
The body controller, by the way, is mounted inside the cab to the side wall next to the clutch pedal, kinda behind where the diagnostic connector is.

 

I read the title and had a mental picture of a thick trail of hair flying out the back of the trailer as the truck speeds down the highway...

 

You should put this on youtube, and your right, I had a dealer tech tell me that same thing your saying. He said your bunk heater wont be shutting down in the middle of the night. Thanks, because Im tired of it doing that. Just go one step further and post to youtube would be nice, unless you cant, i understand. Thanks again for your detailed answer, have a great safeday. I know this is an older post, but very informing and valuable

 

I always appreciate people that actually look through the older posts to find the information they need rather than posting a new question that has already been asked. I would love to post videos, but I am not interested in any legal bs that may follow.

 

I have kind of the same problem on my Lonestar. Only it was cutting these circuits while parked and at an idle. The same circuits that shed are ones that kick when the buzzer sounds. Over night the voltage still reads 12.5 v. Also the display does not indicate load shedding. With the engine shut down and the key on, it will kick them out after 30 seconds. While checking the power source at the breakers the only circuit that never shows any power to it is the auxiliary power source. I can't remember the breaker location, but it is not the cigar lighter, that one works. Could there be a short in that one causing the relay to kick prematurely? There are no codes showing up at all. It just cuts out until you restart the key on position.

 

It could be a weak relay. You can pull out accessory relays one at a time to try to see if one relay produces the same combination of accessories that go dead. Then swap that relay with another one of lesser importance.