I want to swap from clutch fan to e fans on my 04 GMC. From what I understand I can't get fans off a 05 an up unless I swap to bigger radiator. Correct me if I'm wrong. I see that everyone uses ls1 fans are they easier to swap?

 

exact same basically, just the ls1 fans fit a 28" rad and the 05+ fans fit the 34" rad. The harness I made for my fans I used with LS1 fans for a year or so and when I got my 05 fans I plugged it right in.

 

I'm go buy the ls1 fans today from a Salvage yard here in town. Will I need any brackets to mount them?

 

Atomic how did you set up your harness ?

 

It should bolt up with no problems. You can get a prebuilt harness from nelson so its plug and play, youll just need someone to tune your ecm to run them.

 

 

You will need something to mount them up top on the radiator support, just some flat pieces of metal or aluminum pretty much. If you search the GM section for "LS1 fans" you should find numerous pics of different members' set ups

 

LS1 fans are not a factory direct fit and there is some fab work involved in making brackets for it. IMO that was not acceptable no matter how well I build the brackets for both function and appearance. Being that its 12 years old with 154k on it I opted for a new 34 inch radiator so the 05+ fans would work as well as preventative maintenance. I bought everything new and had right about 500 in it all including the harness. The fans I got were actually new Dorman fans for a 07+ new body style Silverado/Yukon/Tahoe and so on. For some reason they were a good 200 cheaper than the 05-07 fans and they fit exactly the same the only difference being the 07+ fans have a spot molded in for the cooler lines to bolt to the shroud for extra support of the lines in the quick connect fittings. The 99-07s never had this so it wasn't an issue and didn't interfere at all. Saved me a couple hundred too. I will admit the Dorman fans are no genuine AC Delco quality thats for sure but the motors seem sound and run smooth. I'm happy with it and I can hang meat in there at idle in direct 110 degree sun and thats just with the fans running on low.

 

Thanks atomic

 

No prob. If you are familiar with wiring you can very easily add in a switch for a manual high turn on. I use it often when I want automatic low/high speed pcm control, but want them on high for when I use the AC sitting still.