Originally Posted by BamaToy1997
Rich, when I was at GM, we had a little 9V battery and a cigarette lighter adapter that we used to keep things like the memory in the PCM, clock, and radio. You just have to make sure you do not open the doors. We would plug the adapter into the power port (Has to be the one that is always live, not key operated) and then get out, close the door, and then swap out the battery.
As to why some have trouble and some don't, I really can't give you a 100% answer. I have had some that didn't bat an eye at the battery disconnected, and others who threw a FIT after a disconnect.
Ya, my Tundra was no problem, likewise for my '94, but even though it was EFI, it was OBD-1
I thought about the 9v adapter... used that on my motorcycle any time I removed the fairing, but the Taco requires the key to be on, and I'm not too keen on shorting the relay.
What I'll likely do some day is rewire the outlets so one is on 24/7 and one is switched. I like the switched outlet so I don't have to worry about the cell charger dumping the battery if I go on a trip and leave the truck parked for a week or more.