I have a 2000 GMC Sierra 5.3L... is there a connection anywhere in the harness to hook up electric fans so the computer can control them?

 

Not in the existing harness, but you can buy a harness like the one from Nelson Performance, and have the computer tuned to turn the fans on. The Nelsons harness was $100 shipped back when I got mine.

 

100 for some wires?... damn i think ill just make my own....

 

Is it needed to have a tune to turn the fans on? Or can you just use a regular temperature probe setup for low speed and tap off the a/c compressor for the highspeed side? Or is it a must for the pcm to control it?

 

i duno but i had wheatley tune mine and he turned them on for me so i duno

 

PCM isn't a must, but it's a nice clean factory sorta way to do it. I've seen temp senders that screw into a water jacket, such as in the cylinder head, there's also the probes that push into the radiator fins (not the most accurate and those probes are prone to failure from what I've read), or you could always wire in a manual switch. Only problem with the manual switch is if you're checking out a hot piece of *** walking down the street and you forget to flip the switch, you could melt down your engine lol.

You can easily make your own, but the Nelson is more than just some wires. It involves 3 relays for low and high fan operation as well as a/c fan operation. It fits perfectly, is nicely packaged, and looks pretty much stock when installed. Electrical diagnosis and wiring is one of my strong suits and I chose the Nelson harness after seeing one in person since it looked so high quality and was about a 10 minute install.

 

anyone got pics on this?
so its a wiring harness and reprogram that he includes?
my trucks fan clutch is going out and i have some 04 escalade electric fans that i want to put in.

my truck is also a 2000 silverado

 

Blackbear also has them link and prices shown below with pic

http://blackbearperformance.com/services.asp

Harnesses are priced at $89 shipped to the US.
Pulleys are $30 shipped to the US.
When purchased together, the price is only $109 shipped.

 

wow looks pretty plug in play harness... not bad at all.. whats the pully for the alt? overdrive pully? how that work?

 

Comes off with an impact wrench.