During my turbo install I yanked the clutch fan to put in some ls1 fans along with a black bear harness. It ran fine for a month but this past week hit 100 and I saw my temps shoot up while in traffic with the AC on. My truck is an 03. The fans dont seem to be moving much air at all. Is there supposed to be a high and low speed for the fans? or is low just 1 fan and high 2?

 

I run a nelson harness, but they should work the same. Low is 1 fan, high is two.

Are you sure they are pulling air and not pushing?

 

If the harness has 3 relays its 2 speeds for both fans, if it has 2 relays, its fan 1 and fan2 at one speed.

Ground the relay control wires manually and make sure the harness/fans work correctly.

 

Also check the connection to the ECM. Do you know what temp your fans should have come on?

 

Sounds like fan 2 wasn't kicking on due to the use of the A/C. That heated things up.

 

Thanks for the responses. They are def pulling from rad and pushing towards motor. Its a 3 relay harness. And I think they are set to come on at 185-ish. I'll try and ground control wires to see if they are working correctly. thanks again.

 

Make sure the relay's are also working properly

 

I beleive I found a bad relay. Headed to the parts store in a bit.

 

Good luck!!!

If you can't find one contact BB ASAP.

 

I was down last weekend, and it was damn hot.