I have a 03 silverado with the 28inch radiator. Tom I'm going to get the electric fans, harness, and 34 inch radiator. Do I have to grab the fuse block with the relays that attach to the fuse box under the hood also to be able to do this as OEM as possible? Is there anything else that attaches to that harness or just the fan harness by them selves?

 

The fan harness it self is part of the headlamp harness assembly.

Part of the harness is pinned into the Main engine harness going to the computer.

 

Cool, thank you. Any thing that best to get the pins out of the harness? The trucks a 05, mine a 03,(both silverado) could I just grab the whole headlight harness from the donor and just swap? Thank you for the help

 

Yeah, best bet is to not cut any wires, but like mentioned above there are a couple wires that go to the ECM. If you have time, unplug the large connectors from the ECMand depin those wires. It will make it simple to put them into your current ECM. I cut the wires and ended up having to rebuild the harness.

 

In case you do miss pulling the PCM harness, like I did, this is the plug you need.
Delphi GT150 Series 2.

 

PCm of NC is where i got my harness for my 01. They make one for the 03+ trucks as well and offer a kit with fans and everything. Will even patch your PCM to command the fans on if you send it to them for free with a purchase of the harness. 100% best customer service,never had a issue with my harness for 2+ years now in az and believe me most of the time the fans are on. I just used a 05 silverado 34 in radiator, set of 05 radiator fans. If you have an aftermarket intake, i had to fab mine a little to get my radiator to fit since it used one of the mounting holes for the rad to mount up. Best mod for the money ever even if your not trying to go performance.

 

Na, I'm going for some performance. Bolt on 5.3 for now, still collecting parts and going to do everything at once. I've been looking for efans off a parts truck for a while now, everyone people usually buy the fans first. We keep having to put each other off for various reasons. I'm gonna get the 145amp alternator, center console/glove box section and see if I need anything else. The oem relay/efan fuse block clips to my 03 correct?

 

Yes!!

 

Thanks brick! Just to let you and a few others know that ya'll are what make this site so great. I appreciate the help from everyone but a few go above and beyond for this forum.

 

Thanks, Good luck with your swap!

I know your trying to do it on a budget. If you do end up needing a harness though, The one mentioned above is pretty robust. I have used them in the past myself and have not had an issue unlike some of the other aftermarket harness out there.