International LT 2020 Sleeper AC shuts off when volts get low, autostart does not kick in.

I will try and find the wires to the no-idle cooling and the module as well. Im thinking it’s a heat issue because it works fine when below around 75 (it shut off last night it was 80 degrees still after dark) I don’t think its outside temperature related as much as it is a heat issue. As in something is overheating maybe. I don’t know if that even makes sense but it’s weird that it works fine when cooler temperatures outside.

 

I try to stay away from forums like this, but I posted a solution to the Bergstrom AUX AC with engine running and saw this issue on the feed thing. Makes me wonder how many other people are dealing with this crap and haven't posted a complaint.

Not sure who this Heavy D person is, but they are totally correct. It's all about voltage drop and what each module needs to see as a load shed strategy. Here's the problem... your average trucker doesn't have Diamond Logic Builder, or a multimeter. They do have a charging monitor on the dash, and an Eaton inverter with a digital display per factory. The charging monitor on the dash is connected to the engine side, and the Eaton inverter is connected to the APU battery pack (back half), which is also connected to all of your bunk HVAC stuff. If the inverter voltage is more than .5V less than the instrument cluster, you have a voltage drop issue. The modules don't know the difference... If your cable ends are hot, amperage can't make its way through.

Your truck will come with a factory emergency terminal to jump/charge the batteries. It's mounted near the catwalk. If you have a bad voltage drop (and you're desperate) disconnect the ground wires on both the front and back battery packs to be safe. Unbolt the main feed (B+) going to your AUX APU battery pack and replace it with your emergency jump (B+). It will reach if you cut a zip tie. Reconnect everything, start the truck, and watch the Eaton display. If the voltage is higher on the inverter, you have a drop issue in the positive cable. Same principle for the negative side, but it's much more unlikely.

Here's a couple of pictures of this issue and the solution. This is from a 2018, but a very similar design. Also, make sure everything is fused. Don't burn your truck down. Hope this helps.