MFU keeps shutting off!!!!!

[Bill 832]

Alright, next newbie question (and don't think for a minute that I don't appreciate all the help!). I have been trying to get the MFU sorted out while the body of the truck is in paint, and everything was ok at first. I strapped the speaker box to the rear of the chassis, behind the coupler, to see what it sounded like, and was impressed. Got the taillights wired up, reverse, coupler sound, fog lights in the bumper of my knight hauler, and am even giving my driver figure his first ride. Then for some reason, the truck shut off sound just keeps sounding every time I start it, and I can't go anywhere! I have reset the MFU numerous times, and am hoping I just have something out of adjustment. I have a knight hauler, and the Futaba T4YF 2.4 radio. Any suggestions? Thanks in advance, and the first truck meet I go to, I'm gonna have to buy a couple of you guys dinner or something for all the help!