Can any one confirm how their pcm control e- fan works ...... 01 V6 Silverado

my pin 42 is enabled and temp set to come as per factory spec ......which is fine for me with 195 stat but not clear on how most of the aftermarket harness's work ......here is how I think it should work ......confirm or correct me pls

engine hits turn on temp ............ both fans Low Speed ??
engine not at turn on temp but AC turned on one fan high ??
both temp turn on temp hit and AC on ...both fans high ??

Is this the correct eway it should be set up ??

Thanks

 

Since you have an 01' your PCM pin 42 will only turn your fans on high, there will be no soft start or low speed just plane old on!!! You should be able to hook one or both to come on with your A/C but not to sure how that works. Hopefully someone will chime in.

 

Thank-you very much for replying you have solved my problem ......I bot a harness and was told it would do the high / low thing 1 fan or 2 fans etcetc .....but it does not as you say both on and on at high speed only yes I can rewire so it comes on when AC turned on just not sure if that will be one fan and when turn on temp reached will the other fan come ....assume so .......realize all this at high speed

So it is not the harness that enables the soft start ..one two, and high low fan functions its the PCM .is that right ??

 

From what I've been told it is the 2005 pcm that does the soft start feature. Someone on here was talking about Jegs or something that had a universal controler that was capable of doing the soft start.

As far as your a/c, I thought Nelson's harness tapped into you compressor wire to turn on one or both fans?

 

Here is some good info....

https://www.performancetrucks.net/fo...ght=soft+start

 

that's the way it should work with a 3 relay harness. that's the way my LS1 fans are hooked up.

 

Thanks for confirming that ......... but what seems confusing is whether it will work that way withthe 2001 PCM .......I get conflicting info

 

yes, it will. White1 sold harness (as has Nelson) to many people with different year trucks. They are all the same. I have his original 3 relay harness on my truck('03), then he built one for his own truck ('00).

*The PCM sends a ground when the fan temp is hit, that will turn both fans on, low speed.
*The A/C clutch wire gives a 12v+ signal this will turn one fan on at high speed.
*If both are true then both fans run high speed.

I have helped install several of these harnesses. If you are interested in a harness then send a PM to DLH2006, as long as they are turned on in your tune it'll work just fine.

 

Thank -you very much ......I bot a harness from my PCM tuner ( not Nelsons ) it has only 2 relays and it turns on both fans on high when temp hit .....when I questioned operation he did say I can hook one on the trigger wires that goes to the pcm to the AC but was not clear on what will do assume turn one fan on high does the harness control the high low setting of the fan speed .......will try that or may just buy a new harness

remember this is a V6 not sure if pcm differnt than V8 for this fan deal