got my 05 electric fans on and am working on the tuning...

using hp tuners went to aux fans on at 180 of at 169 second fan on at 179 of at 168 but the problem is that the fans are never coming on. now the nelson fan harness to check my connection pulled the pcm harness of and grounded pin 42 to the battery and the fans kick on so i dont know what i have done but wanted to know if anyone knows what i am doing wrong with the tuning to make it to where they will not come on by the pcm telling it to i no that it has to be in the tuning because it does work if i ground the connection out.

thanx in advance
zach

 

I used the box "two fans" instead of auxfans on my truck.

 

i tried both ways and still it is a no go

 

https://www.performancetrucks.net/fo...d.php?t=377292

http://www.monodax.com/forums/tunerc...-98-chevy.html

 

I have aux fans on mine and they work fine. Double check the pin 42, make sure it pushes "ALL" the way in, when i did my tranny swap, i forgot to push the pins all the way in and i had problems read VSS. But that's what i would do, sometimes those pins can be a bitch to push in, make sure they make a little click noise.

 

The second fan temp settings will not do anything unless you have a harness with 2 wires to the PCM and I have not heard of anyone doing that. I am guessing you have a 160* thermostat if you are wanting to try and run that cool and I would think that even if you do have a 160* stat with those settings your fans will probably run non stop when you get them working. From what I have heard you may want to set those fan settings a bit higher. Of course you can work that out after you get them working.

 

I was just gonna suggest the same thing

 

And now you have...me!! Here ya go.....start @ page 4 for the good stuff.

 

the nelson harness will not work with both fan controls in the pcm. you only get one pcm fan setting and one a/c clutch enable.
I'd suggest sence you have a 04 (which can support both fans, using pin 42, and 36 I believe), that you rewire the nelson harness so that it has two ground controled relays and not just one.....