I've started having a overheating problem. I noticed the fans are only coming on with the A/C is on. I tried lowering the enable and disable fan1 and 2 temps and increased the fan1 disable speed, no help. Yesterday I noticed the fans were off and the engine was over 220, turned the engine off and back on and the fans were runing.

The fans always work in A/C mode, so no loose wire at fans

Wouldn't I get some kind of check engine light if the ECM lost its signal from the temp sensor?

Would a header touching the factory oil cooler be a bad thing?

 

fan relay, trust me happens to me every 6 months