hat up to everybody i have 2003 Chevy Suburban Z71 1500 5.3 l i just finish installing black bear harness custom tune to turn pcm on for fan pin 42 problem i having soon battery hookup fan start running high passenger side without key on or engine running i pull the relay keep from kill the battery good thing when truck reach temp left fan come on what wrong why is fan run wild thank you alken26

 

Sounds like you wired up pass.side fan incorrectly. Recheck your wiring.

 

yes i did wired incorrectly pcm pin 33 was splice to a/c relay fuse block i install plug #33 into empty spot #33 in pcm Fan are operating normal thank for help. and like this site has lot good subject. keep up the good work.