not sure where you live, but you might want to check cables underneath. Had a friend who had a similar problem with his jeep. Was driving him crazy, and he finally saw that some critter chewed an electrical cable that shorted out. When he was trying to jump start it, his cables started smoking...
Love the bed idea. We stopped camping because we got older and hated the text thing. Backs kill us now. lol. Will need to look into this for my wife 2003 4runner.