Tonyrodz
Resident Resident
Which scanner did you get?
Saving a few NBS'ssss
- Thread starter drowssap
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
bottomline2000
Full Access Member
What you just said is EXACTLY why I had such a problem getting this install done correctly the first time go round! All of the aftermarket harnesses I guess color coded to the corresponding plug! BUT....if using the factory harness....it was the opposite. Oddly the 03-04 guys are in small numbers. This was a big mod on 00-02 and for some reason not the later. Then to make it worse all you can find is info pertaining to the A/C trigger and so on. I was just grateful to have access to the 05 to rip it open. On a side note one thing that everyone mentioned was how difficult it was to remove the pain in the arse grey plastic covers from the ecu plugs. I got that one down flawlessly and should probably post that info somewhere to help others out.
Here is the ONE guy that changed everything for me!! For a good laugh....fast forward to the 4:10 mark and listen to how he describes where the wires go. His description sent me into a panic! HAHAHA
Just reference Scottys harness thread to keep things simple..just for reference my Nelson harness has a blue wire for the pcm tap and green ac wire tap.
Sent from my SAMSUNG-SM-T377A using Tapatalk
Last edited:
bottomline2000
Full Access Member
If you ac or defroster was on the fans may come on briefly even if the engine is not up to temp. They should NOT be on all the time. I ironically have my original pcm which did run my fans full time after Justin tuned my truck. My truck had a unique OS and this caused the problem. I had to switch to a 0411 pcm to fix the problem. He shouldn't have had to do anything with yours since it came ready from the factory.
Sent from my SAMSUNG-SM-T377A using Tapatalk
adventurenali92
Full Access Member
I’ll have to look at all of that when I get home tomorrow, and see what’s it’s doing.
OP
OP
drowssap
Full Access Member
Hilarious! The truth is that I wanted to contact you and was very desperate but you didn't appear to be online! Between you and scotty I knew I would get the correct answer but it was getting late and needed to button the truck back up. On a side note....thanks for following the tech threads and continually help!
OP
OP
drowssap
Full Access Member
Yeah what @ScottyBoy offers to forum members is awesome. A harness from him was actually on my list until I stumbled upon a complete low mile set up at the yard. The conversion work is cake but properly removing the harness from donor cars is work! Then to clean them up and offer a great product is just awesome of him to do.
As far as what made me try to figure this out was the fact that I knew enough about my install after reading A LOT was that both wires needed to go into the pcm. I remembered 42 and 33. When I finally installed my setup and went to connect the wires it hit me that I never found info pertaining to exactly what went where. I left the garage and spent 2 hours scouring the web and all I could find was the one video that I posted and he did not give me the complete confidence I was looking for! I knew I had the 05 to inspect but that truck was outside in 20 degree weather in the dark and my neighbors do not take kindly to me wrenching AT ALL! I quietly went out with tools in hand and a headlamp and started digging!
OP
OP
drowssap
Full Access Member
Managed to get a good amount completed which is great because I won't have a free minute to tinker for another 7 days. I want to make sure that every square inch of this thing is where it should be to help me have a great starting point for mods. Only 3 items left and that is to reattach fender flare, alignment, and turn on PCM pins for
e-fans. I am happy!
e-fans. I am happy!
Last edited:
ScottyBoy
Full Access Member
I know that I am late to the party, but it looks like you got the fans all figured out. The blue wire is the AC trigger and goes to pin 33 which is in the green connector on the PCM and the green wire is the temperature trigger wire and goes to pin 42 on the blue plug on the PCM.
On a lot of aftermarket harnesses, I think they reverse the colors for ease of installation. Because blue to blue and green to green is FAR easier to remember. Plus on the 99-02 trucks when connecting to the AC compressor wire, that wire is green. So splicing another green wire into it is a lot easier to remember how it goes. But the OEM harness is the opposite.
Actually that info is wrong. That's why we have conflicting information because people are used to using aftermarket harnesses which have the cord backwards. The blue wire is the AC wire/high speed fan trigger wire and goes to pin 33. The green wire goes to pin 42!! On your harness that I converted, the blue wire goes to the AC compressor wire.
On a lot of aftermarket harnesses, I think they reverse the colors for ease of installation. Because blue to blue and green to green is FAR easier to remember. Plus on the 99-02 trucks when connecting to the AC compressor wire, that wire is green. So splicing another green wire into it is a lot easier to remember how it goes. But the OEM harness is the opposite.
ScottyBoy
Full Access Member
Look at my install thread, I covered all this back in 2011 when I installed my Efans.
http://www.tahoeyukonforum.com/threads/i-installed-e-fans-on-my-2001.28336/
Here is a diagram for further clarification as well. I know it's hard to read, but the green wire goes to connector 1 (C1) at the PCM pin 42 and the blue wire goes to connector 2 (C2) pin 33
HOWEVER, in the case of a 99-02 where you are using the AC compressor to trigger the high speed, then you would wire a relay to the blue wire like I show in my install thread linked above.
http://www.tahoeyukonforum.com/threads/i-installed-e-fans-on-my-2001.28336/
Here is a diagram for further clarification as well. I know it's hard to read, but the green wire goes to connector 1 (C1) at the PCM pin 42 and the blue wire goes to connector 2 (C2) pin 33
HOWEVER, in the case of a 99-02 where you are using the AC compressor to trigger the high speed, then you would wire a relay to the blue wire like I show in my install thread linked above.
