The only thing the a/c does, if I run it, is kick one of my fans to high. It does not go from off to on. One of my fans is on 100% of the time. The other kicks on at a certain temp (I set it to come on and stay on once the temp is reached), then kicks to 100% power for a/c.

 

Explain to me how yours are wired and how they run given the different circumstances.

FWIW, I have a switch that sets both fans on high regardless of the inputs, and I still have overheating problems when they are set to high and stay there without cycling.

 

lots of good points in here. thunder amp probe EACH fan, what is the initial start up of each fan and what is the running amperage of each fan. EACH. They should be the same. and like white points out, if they aren't happy they will have high amperage due to degradation of the motor. So they (or one) might not be efficient enough to cool your system.

I just got off a conference phone call (Monday) with an exhaust fan manufacturer, we had to convince my customer that the exhaust fan being wired to run constantly will more than likely last longer than turning it on and off a bunch of times during the day. AC motor, but same theory. I am with BC on this one,

 

DOH, kill my last post then. That answers a few troubleshooting questions.

hmmm...but are they running as effiecient as they should. I take that back. I still say test each fan to see if they are running in their "manufactured specs".

 

So the 34" radiator went in the same time as the LQ9 and 05 fans. right?
But the 5.3 was overheating with the mechanical fan aswell? What did you use from the 5.3 when you did the swap?? water pump? ect?

 

With the 5.3, clutch fan, stock 27" radiator, and stock thermostat everything was fine. When I went to e-fans, all I changed was the radiator and fans. I still had the stock thermostat, it was still the 5.3, and it was still the same water pump. Overheating issues surfaced here, so the problem is either the fans or the radiator because those are the only two things that changed.

Since then I have swapped engines, and gone to a 160* thermostat, but I am still using the same water pump. Still having issues. If the clutch fan I bought doesn't fix the problem (I will be installing it tonight and towing with it tomorrow) then the problem HAS to be the radiator.

 

Id put my money on the radiator. It is possible the fans are going out too, that would explain the relay issue, just seems like they would have completely died by now.

 

The radiator was a brand new one from Performance Radiator - I wonder what could be wrong with it? If the clutch fan doesn't fix the problem (I'll know tomorrow for sure) I guess I'll be pulling the radiator out and taking it back to PR to have them look at it.

 

Mine is wired like I asked Allen to do it. I wanted one on all the time and the second to come with the A/C or the truck reached the cut on temp.

 

Well got the clutch fan installed today, the shroud I got with it is for the 27" radiator, I'm gonna have to go to the dealer I guess to get the one for the 34" radiator. I'll know tomorrow for sure if this is gonna fix my problem or not. I really didn't notice any difference in power going back to the clutch fan.

The clutch fan feels like it is pulling more air at idle than the e-fans did together on full.