Sure it will work just fine having them all powered when the key is off, but I wouldn't do it that way. If you do have an issue with a circuit (say between the switch and the fuse box), then you need to get to the battery to disconnect it while your truck may be trying to light on fire. There are many circuits that don't need power when the key is off. This is as much for safety as theft deterrent.


1946 GMC Pickup - S-10 Frame, 455 Buick, TH400, original patina.

My 46 GMC on Photobucket