Parasitic loads - GM trucks & SUV's

rockhillmanor wrote:
Hit the override switch for interior lights. . .

OP here.

Thanks! I’ll check for how to kill that feature. Or maybe I'll pull out some bulbs. I already have the habit of turning the off the outside lights when I turn off the ignition after dusk.

I may figure out which wires to pull or cut to kill the OnStar feature that is supposed to be a fair power drain, even though I don't subscribe and have never once used it.

With or without the Tomtom, it makes no difference. That was the first thing the dealer questioned, but the measured draw is negligible when it is shut off. And, it is always shut off unless I’m using it.

It is well-established that SOME (not all) GM trucks & SUV’s from 1999 onward have this intermittent (not constant) problem of something drawing the battery down. I happened to draw the short straw, I guess. Something that stays on after ignition turn-off and is supposed to shut off after a while sometimes does not shut down. I’ve made several trips to the dealer while it was under warranty and, naturally, it does not act up when they have it in their shop. They were kind enough to replace the original battery under warranty. Their only solution is to make sure I run it often or plug it in to a maintenance charger.

This is enough of an issue that some businesses exist for catering fixes for it, such as http://www.atct-guardiansys.com/

Yeah, I’m concerned about the deep discharge ruining the nearly-new battery. I don’t want to be stranded somewhere very remote if the battery suddenly dies

I’ve thought of one of those dashboard solar chargers, but I have only one 12-volt outlet. (Thank you GM! My last truck, a1998 Sierra, had 3.) I’ve considered hard-wiring a dashboard solar charger. Or, maybe I could look into getting another outlet added. (I’ve tried several splitters attempting to use both Tomtom and cell phone charger while driving and they won’t stay in contact with the crappy outlet socket GM used.)

I’m not sure how many watts of solar I might need to keep ahead of the intermittent parasitic load, since no one has been able to measure that load. Something is better than nothing, I suppose.

Wayne