I noticed with my ( 08 RRSSC) cooler box, that it will only be on, IF the truck is in drive and moving. If you stop at a light for a period of time, or in stop and go traffic, I've noticed that it turns off. Maybe because it's chewing up so much power and the ECU is programed to shut it off to save stress on the engine & altinator??? just my 2 cents. :dance: