I figured as much. So you need a harness from a 2003 through 2007 or an aftermarket harness...

 

Yes, from what I have learned today I think that’s my only 2 choices. I have plenty of time to find one and if I don’t I will use an aftermarket one like PCM of NC or something similar. They claim no cutting or splicing and that’s what I’m looking for.

 

I just ordered the fan Assembly from LKQ and I think I will be better off with the used OEM setup. The 2008 Denali has 53k miles on it and it’s a California car. It has the tow package and it has a 7 blade and a 9 blade fan Instead of the 5/7 or 7/7 I don’t really know how much of a difference it makes but a few xtra blades can’t hurt. I got it for 116.57 including taxes and shipping. That’s as cheap as I found a factory setup with that mileage. I found some good Assemblys at Rockauto from 154 to 260 and they are 7/9 blade fans and that was my first choice but went a different direction.

 

Mixman the seller sent me this image and it’s just like you said. I was curious about part #5 and wondering if that harness could be purchased? Maybe this will help others looking to do the same thing.

 

It is not available as a separate wiring harness. In the part systems for that picture view #5 says see fwd lam harness diagram for detailed view. Then you pick from one of the item #1

https://nemigaparts.com/cat_spares/e...k/02/tc02-211/

of which there are about 50 variations depending on the specific vehicle options and equipment....

Trust me. You are not going to find a shortcut or some easier way..... hundreds of people have already researched this in depth. The only easier methods are unreliable aftermarket solutions. For something this critical, its just not worth the risk of things failing or not working right.

That part site I just linked - save that.... Excellent resource for locating various part numbers.

 

I see that #5 is a huge mess of wires. I called BP Automotive and asked them a few questions about the harness they sell and after reading the instructions and getting good answers I’m leaning towards their product and I like how it mounts the relays under the fuse box lid. I also ordered the oil cooler lines for a 2008 H2 so that will fix the problem of the fan Assembly hitting it. I dropped my H2 off at the transmission shop this morning and Bob said maybe Thursday it will be done. Big week for my little piglet. My used fan Assembly will ship out today also.

 

One important point on the electric fan conversion. Do not install the electric fans until you have your custom tune done... Accidentally did that once - realized pretty quickly that was going to overheat on a test drive. lol

 

I see how that would be easy to forget. My plan is to have it done before I start the conversion and I need to start looking for a tuner to do it.

 

Typically from what I've seen the fan settings are already in the tune but may be turned off for this model truck

I could not find a H2 07 stock tune but I did find an 06 stock tune, going to download and look around and see how its setup

Neal

 

Thanks Neal for looking. I would like everything set to a lower temperature than stock I think or that’s what I want until someone talks me out of it. I have a 160 t-stat and I’m thinking I want it setup around that. Without looking at what it should do I’m thinking maybe 15 or 20 degrees cooler perimeters then stock but I will ask the tuner what he normally does.