Compatible with Chevy:
For Silverado 1500 pickup 1999-2006
For Silverado 2500 pickup 1999-2006
For Silverado 3500 pickup 2001-2006
For Silverado 1500 2500 3500 pickup 2007 classic style (creased dr skin)
For Escalade 2002-2006
For Escalade EXT 2002-2006
For Escalade ESV 2003-2006
For Avalanche 1500 2002-2006 , For Avalanche 2500 2002-2006
For Suburban 1500 2000-2006 , For Suburban 2500 2000-2006
For Tahoe 2001-2006 , For Tahoe 2000 Silverado style

Compatible with GMC:
For Sierra 1500 pickup 1999-2006
For Sierra 2500 pickup 1999-2006
For Sierra 3500 pickup 2001-2006
For Sierra 1500 2500 3500 pickup 2007 classic style (creased dr skin)
For Sierra Denali 2002-2006
For Sierra Denali 2007 classic style (creased dr skin)
For Yukon 2001-2006
For Yukon XL 1500 2000-2006
For Yukon XL 2500 2000-2006
For Yukon 2000 EXC. Denali

Describe:

The wiring harness includes a custom relay and circuit breaker installed in the original enclosure of the fuse box.

Installation is simple. Simply mount the relay hub on the fuse box cover using the hardware provided, then connect the power wire,

ground wire, two ECM control wires, and plug the two fan plugs into a set of fan truck electric GM 2005 or later.

When FAN 1 starts correctly, both fans will be at low speed, and when both FAN 1 and FAN 2 are started, both fans will be on at high speed.

OEM fan assemblies are only available for 34" wide radiators. If your truck has radiators of different widths, then you should also upgrade your radiators.