does anybody have this diagram?? thanks.

 

https://ls1tech.com/forums/showthread.php?t=220998

Note: The PCM 17 connector is incorrect in both images. It should be the A/C clutch compressor circuit.

 

The 3 relay solution looks like a great setup. Which did you end up using on yours?

 

I went with two relays

 

i recently installed a set of fans on my suburban and i did the same set up as on my truck but this time i did not use the relays. THey work fine and cool the engine properly but my question is what exactly are the relays for?? Thanks for the feedback in advance.

 

Well, I'm no electrician, so I can't explain it, but I had the same question when I installed my water pump on my car, way back.

I don't really remember the explanation I received. Hopefully, someone here can explain it.

 

SS, Relays are generally used for higher current applications. They will carry a higher amperage load. You should use relays to power high amp electric fans. By having 3 relays you allow the option of the fans to run at half power when just the pcm calls for cooling. The wiring is routed by use of the 3rd relay such that the fans are in series basically giving them 6 volts of power. I think? and half speed. When the AC is turned on and the compressor relay is pulled in it switches the 2 fans via the 3rd relay from a being in series and half power to being a parallel circuit and full 12 volt each therfore full power and speed.

 

ahhh i c thank you.