Good Evening,
I purchased a 2013 Sierra 2500HD back in August. It has the 6.0 motor. Has 45,000 miles currently. Back in November the fuel pump went out while driving. Replaced it with a Delphi Pump. The OEM was on backorder. Was leaving on a trip in 2 days so had to go with the Delphi. Besides changing the low beam bulbs and battery this is the only change prior to my current issue:
Truck sat a couple weeks since I have a company vehicle. Went out and had no dome light, no instrument lights, no crank, absolutely nothing. Looked around for anything left on, door not latched etc. Fully charged the battery.
Used a multimeter to check amp draw/milliamp at battery. Gave it 10 mins and it showed 0.001-0.002. Seems like it should have more than that so kinda question my meter.
checked millivolts on fuses and all went to 0.0. Some larger fuses and relays do not have exposed metal but checked what I could.
picked up a foxwell battery/starter/charging system tester. Tested 796cca and is rated 760. All other tests came back fine. When finishing up noticed a led illuminated on a switch overhead. Truck is equipped with snow plow package, and the switch is for auxiliary lighting.
to my knowledge nothing is hooked up to it.
I cant see a switch being on with nothing connected to it would cause such a drain. The headlight on warning chime is also intermittent. What am I missing or what else should I check? Something just doesnt seem right.
unfortunately not owning the truck long and not driving it everyday makes it harder to notice things. I use this to pull our travel trailer and dont want any surprises.
sorry for the long explanation but felt it may help with troubleshooting/conclusions.