I just installed the PCM harness for my LS1 fans today. I have a 160* thermostat and Nelson setup my PCM to control the fans. It doesn't seem to keep a steady temperature. Is this what everyone elses does? Seemed to cycle between 185-200* on the dummy gauge.

>5.3L ECSB 4WD 85* outside today

 

anyone?

 

Sounds like air in the system to me -- need to get the coolant purged

 

mine does it to it will actually get to 200 setting in traffic and then i can drive a block and it goes back to normal about 175-180

 

Yeah mine come on at 190 and go off I think at 178 but I'm not real sure on the going off temp but I know for sure that they come on at 190...

 

Mine run about 185 on average and as high as 200 if sitting in traffic with no good air to draw in. I have a 180 t-stat. It is still way better than the stock manual fan and thermostat which was always over 210 no matter what.

 

I recently installed a 160 thermostat on my truck. I checked at the performance shop and they told me that hypertech didn't make 160 degree thermostats for the '04 or '05 trucks . So I went to the auto parts store and asked for a thermostat for an old model car (like a 69 camaro). Thing worked like a charm, fit right in there...my buddy made a mod on it with a bit drill, one little hole and installed it. Another friend of mine did the same thing with his '05 truck, but it is still going up to 196 - 210. He blames the electric fans but i don't know...any ideas what's going on with his truck?? I've been looking for some e-fans for mine, but he's making me doubt about them...

 

I noticed the temp moves around a bit with the efans as well. With the stock clutch fan, the guage pretty much stayed glued in the same place once it warmed up.

 

My gauge never goes above 200, hangs out @ 185 unless sitting w/ AC on/ or Dynoing gets close to 200 but falls fast to 185.


180 degree t-stat
Flex a Lite w/ manual temp adj.
Reading 190's w/ HPT right after a run.

 

looks like a lot of you are having the same experiance. like jm said the clutch fan would hold a steady temp, and I'm not seeing why the efans can't. Even with my 160* stat the clutch fan would hold it steady at 185ish untill the AC was turned on.
So has anyone been able to hold a steady temp with their fans? What are the ON temps you are using in your PCM if you've got it figured out?