Mind posting more on this.

 

"This way lets you know that all your fuses and relays are In working order:
Wire in LED where the positive side is connected to Relay #1 PIN 87. Ground the other side. This lets you know the relay has power and is sending it to Fan #1.
For Fan #2 hook the positive side of LED to either Relay #2 pin 87 or Relay #3 pin 87A. Ground the other wire of LED"


https://www.performancetrucks.net/fo...-101-a-494123/

 

Might have to do that. Just need to find a inconspicuous place to mount the LED's.

 

Well both fans come on low if I let it idle and come up to temp. But if I turn on the AC it does not kick one on high.
Ok on the factory harness I did some searching. Are these 2 blue wires supposed t be together??


just to test I unplugged one fan while it was running and after a few seconds the other would kick on in high and then I would plug in the other fan back in and they both would run on high untill the comp kicked them off. Im soo confused.

 

Thats why i like building my own harness..


Can you ground one PIN and both fans come on low?
Ground the other PIN and fan 2 comes on high?
Ground both PINs and both fans come on high?

 

Yes I just went out and did that. i grounded the green lead and both came on low and then I grounded the blue lead and one fan came on high and then grounded the both and they both came on high. So im assuming the harness is working. So I put it back together and started the truck and hit the ac on and both fans came on . Here is what the relays look like


Im beginning to think its in the tune??

 

The pin that turned Fan #2 on high. plut it in to the pin 33.
Pin that turned on fans low, plug it into pin 42

If the AC turns on fans on low, your good
if Temp turns on Fans low, your good
if ac is on and the temps are up to the setting, both fans are on high, your good.

 

If i were you, id ask justin for a screen shot or a list of parameters for the Fans, and get some type of scan gauge so you can watch your Coolant temps and such. I use a ScanguageII and it comes in handy all the time!

 

I am wondering if the relays have anything to do with it. This guy here (https://www.performancetrucks.net/fo...-chevy-484892/) has different # relays than I do. And I do have the pin for both fans on 42 and high fan on 33.

 

could be different year harness?

You need two 4 pin relays. and one 5 pin..
pull your relays one at a time and see what they are..