Check the power wire? Also make sure the plug in back didn't become dislodged. Just a couple of ideas.
Dave
2003 Silverado SS here's where my money went...Radix @ 9psi, Vortec IC tank, Oversized Heat exchanger, ASM LT Headers, Suncoast Ram Air hood, Airaid intake, Trailblazer Torque converter, Full billet servos, Zippy kit, cat-free, Flowmaster muffler, Gaylord Speedstur tonneau, 3/4 drop with Belltech spindles and leafs, Sirius conversion & MTX thunderform sub box. 05 e-fans coming soon!