eHoefler wrote:
There is no way the truck, especialy at idle, will keep up with the demand of the furnace and lights, let alone charge the battery. The most you will ever get out of the truck is 30 amps, with the length of run and voltage drop, you'll be lucky to get 20-25 amps at the plug. It is not so much a charge line, but a keep alive line.
My experience (as measured with a DC Amp meter) is that my truck will only charge about about 2-3 amps with the OEM sized wiring.
If I remember correctly, up through 2015, GM trucks aren't wired by default to charge - the charge line isn't connected under the hood. The wire is there, but not connected to the aux power terminal, nor is a fuse in place that powers that terminal (post)