Product Details Brighten Up Your Driving Experience With This Simple Upgrade Inside Your Fuse Box. Simply Install The Gm All Lights On Module To Allow Your High-Beams, Low-Beams And Fog Lamps To Simultaneously Illuminate The Road Ahead. Once Installed The Gm All Lights On Module Will Turn On The High-Beams, Low Beams And Fog Lamps When You Turn On Your High-Beams. When The High-Beams Are Not Turned On Your Low-Beams And Fog Lights Will Function Normally. Fitment For 2001 - 2007 GM Classic Full Size Truck platforms including: For Silverado 1500/2500/3500 For Sierra 1500/2500/3500 For 2003 - 2006 GM Classic Full Size SUV platforms including: Avalanche Suburban Tahoe Installation 1. Remove the relays labeled: FOG LP, HDLP-LOW, DRL, HDLP-HI 2. Lay the GM All Lights On circuit board in the location shown below 3. Reinstall the four relays back into their original location Package Include1/2/3/4 Pcs