So heres the story, I bought a 05 chevy that had front end damage, the truck came with almost everything that needed to be replaced excepttt..... The E-fans. I had some that came off my 08 Sierra, they fit and plugged in but don't turn on. Does anyone know if they will work or maybe the connectors don't work?? I checked the grounds they all seem fine and tomorrow I will buy new relays, I don't know where the temp sensor is at? Do they turn on with that?? Is it the one on the block, driver side??

 

Temp sensor is in the driver side head. Have you brought the truck up to operating temp and they still don't turn on?

 

Yup. Went a little past 210 and I shut the truck off.

 

I just checked a stock tune for a 2005 Silverado (assuming thats what you're working with) and fan on temp is set to 226°. Let it heat up until that point and see if the fan turns on. If you see 230, shut it down and have someone look at the tune.