Hey fellas I have a 01 Tahoe and it has the 34 inch radiator and I bought the 05 electic fans to put on it . I would like to hook up the fans but I was told if I want the Pcm To control the fans I will need a tune so the Pcm knows they are there but how would the Pcm kow they are there if they didn't put E- fans on til 2005. I'm just a little confused about that part. I used to have the Flexalite 282's on my truck until the VSC burned up and fried the fan's . Flexalite replaced the fan's and I got a tune from Nelson and bought one of his efan harnesses but that didn't quite work out for me. So I just when back to the clutch fan. The gas prices are just to damn high and would like to get those 2-3 more miles per gallon again. Is there another way of hooking these up and having a toggle switch for back up. Please any help will be great.
Danny

 

Could you elaborate more on what didn't work out?

 

The PCM has option to control the fans but unless the truck came with them the option is not turned on. What is meant by getting the tune is basically turning on the control and putting in the temp setpoints for the cycle on and off at. You will also have to have to wire them up to take advantage of the PCM control.

 

I bought a harness for my 05 truck fans from Nelson...but he didn't mention anything about changing the programming. Will I have to have it changed? This is exactly what he said:

The fan harness we supply comes with everything you need to get your fans
working correctly. I supply the OEM connectors for the ls1 fans and
additional hardware for the flex a lite fans. The harness is completely
wrapped in loom, all joints are soldered and I use fusible link instead of
fuses, just like your starter wire.
To install, you simply supply ground and power, tap into the a/c green wire
and push the supplied wire and terminal into the pcm. All ground, power and
a/c points are at the red junction box on the side of the driver's side
engine. So there's no hunting for wires. The pcm wire simply pushes into
the blue connector at pin 42.
The harness has three speeds. Here's how it works.

The pcm is programmed to ground pin 42 when it reaches a turn on value and
off when it reaches a turn off value. When it does ground the pin, it will
activate both fans and turn them on low speed.
When the a/c is turned on, the green wire has 12volts applied; both fans
will turn on high, as long as the pcm has reached its turn on value.
If the engine hasn't reached its turn on value and the a/c is turned on, one
fan will turn on high. This will keep the a/c cool.

 

yeah you'll have to have the programming changed. how's the pcm going to know when to turn the fans on? magic?

 

I dunno...from Allen's description it sounded like it was already programmed to do it from the factory "The pcm is programmed to ground pin 42 when it reaches a turn on value and off when it reaches a turn off value."

 

Must be turned on. Find a bud with Edit or HpTuners. 5 minute or less job.

 

Phx buds being recruited here
https://ls1tech.com/forums/showthrea...39#post2908039

 

ic, no offense meant there. he should have mentioned it as having the ability to be programmed for it.

 

None taken.

I got ahold of Allen today and he explained what was needed, said if I can't find anyone to change it for me I can ground it manually and put a switch on it for a temp fix.