Quik

iTrader: (7)

been doing some researching and came up with a few ways to wire up the fans. one way is factory way which houses 3 relays and two pins. 33 and 42. now if you use thsi way does an 02 PCM have the ablity to work with the two pins. i know 42 for sure but how about pin 33?

now if can only use pin 42 which is low speed. is there any cooling issues? with fans not coming on full speed?

im not buying a harness when easily can make my own

BlewSilverado

iTrader: (3)

I noticed no one has replied to this thread. Not trying to high jack it just asking a similar question. I have a 04 that I bought the factory fan harness for with all of the relays and plug ins included. It has a blue signal wire which I asume should be wired to pin 42 and a green signal wire that I'm not sure if should be hooked to pin 33 or not at all. From what I gather I need to add one more relay to kick the fans on high when the AC comes on but im not sure how to do that. Has anyone on this site used the factory harness instead of a Nelson harness? And if so how did you do it? Also with a 160 thermostat what temps do you set the fans to come on and off at?

.T.

Quick- here's a link to a thread I used a couple years ago when I did my 04. I think it's all in there.

Blew, a stock harness would be insane work just to wire fans.

405hpta

iTrader: (1)

NELSON harness FTW...

nonnieselman

iTrader: (10)

Its too easy to make a harness!!!!!!

I made one up for this kindof set up..


Low speed (both fans running with 6volts) i can get my coolant temps up to 225 and turn them on and in just a mintue the temp will go back down to 196. Ive sat with the A/C on for along time and never had a issue... so i wired them up like the pic shows above... no problems yet.. and the low speed is very quiet which i like.

Its very easy to make also... 2- 4 pin relays and 1-5 pin relay and some wire with 1/4" spades... few minutes and your ready to rock.

BlewSilverado

iTrader: (3)

I already bought the factory harness which had the wiring for the fans and pretty much all the lighting sockets and wiring for the front of the truck. Basicaly I had to seperate the harness and just use the fan portion. I have a friend that works at a dealership he got me the harness for $150 which I know is high but at least I know its right. Basicaly the harness has a power wire, a ground wire, a low speed tigger that activates both fans on low and a high speed trigger that activates one fan on high. I am going to hook the low speed trigger to pin 42 and the high speed to pin 33. My biggest question is how can I get the fans to come on when the AC is on. I am going to have to find something in the AC wiring to activate the low speed fan trigger. Does anyone know if there is something in the AC wiring that will ground when the AC is on instead of a 12v positive?
Here is a picture of the factory harness.

http://i112.photobucket.com/albums/n..._0475Large.jpg

Tig

iTrader: (2)

I like your idea BlewSilverado. Simple and looks factory. Do you have a part number for the harness? I'm what you would call "electronically challenged"
I had an e-fan kit for my old truck, it was three wires, two for the fues box and one for the temperature. Took me no time to install. Thats what I like, a simple install.

Thanks

BlewSilverado

iTrader: (3)

The GM part# is 15216042. I think it was for a 05 Avalanche. Ive seen different part numbers in other post. Im not sure if there is a cheaper harness for a different vehicle that could be used.

.T.

If you want a simple install just buy Nelson's. It'll all but jump in there and hook itself up.

Tig

iTrader: (2)

Thanks Blew, I appreciate it.

.T.
Do you have link?

Thanks

the easier the install the happier I am