Just a thought, yours is a 2003 as is mine, pulled mine out because I got tired of the problems I was having, when I pulled it all out I found a "air inlet filter" tucked up in the rear drivers side fender well that was rusted up and it turned out that it restricted air going into the compressor so it would shut down the compressor after a couple minutes of running, then next time I would start the truck and it would do the same all over again. May not be your problem but if the compressor cannot get air to push into the bags it will shut down.
12th post down in the link below.
http://www.elcovaforums.com/forums/s...ad.php?t=24471
Good luck and if HUMTECH does read this he will try to help you out also.
Ed