brewster240

who makes a 2 wire harness for 99-02?

GMCtrk

iTrader: (27)

Oem. Get one off an 05-07 truck.

brewster240

oh ok, let me check the home depot parking lot.

i asked because you said "aftermarket 2 wire harness instead of 1 wire harness"

2xLS1

iTrader: (25)

Just order the 2 wire harness they sell for the 03+ trucks and put it on a 99-02. I think everyone that sells the 1 wire harness also sells the 2 wire harness. They just tell you that if you have a 99-02 you have to use the 1 wire harness and that is just wrong. It installs just like it would on a 03+. One wire to the blue pcm connector and 1 wire to the red or green pcm connector.

A quick google search came up with this one. I don't think I can say who sells it because they are probably not a sponsor.

brewster240

the problem with that is pin 33 seems to be taken on the 99-2002, so where does that corresponding wire go at that point?

2xLS1

iTrader: (25)

You use tuning software to change that pin assignment from auto air recirculation to fan 2 control. Simple to do.

Nelson Performance

Why go thru all this frustration and not just call?

Why do we still make the 1-wire harness?
Because the second we tried retiring the harness, customers demanded we offer it.

We have made huge improvements to the harness, actually a while back.
Sealed, weather tight relays. If someone has had an issue with a harness and the new sealed relays were causing an issue, we haven't heard about it.


Be sure to go thru the troubleshooting process to determine if the harness is at fault, or not.

You can reach us at 210-626-0278

Nelson Performance

It's not wrong.
If the customer doesn't want to rid the truck from auto recirc, then they can not remove this wire.
Some 99-02 pcm's have this pin taken and some don't, and most customers don't feel comfortable removing this and losing the feature.


The pic you just posted; that's the type of relay and connector that allows contamination to cause contact issues.
That is the type of relay and connector we used years ago.

Here is our harness.

2xLS1

iTrader: (25)

Every person I have edited the PCM for after installing your 1 wire harness was thoroughly pissed when they realized they were only going to get high speed fan operation when the A/C compressor engaged. And every one of them had never even heard of, or realized that their vehicle even had, or would even enter an auto air recirculation mode. There was a time when the tuning suites did not offer the ability to reassign the fan 2 pcm pin. Those days are gone. The days of selling the 1 wire harness should be too.

Mikey 97Z M6

iTrader: (35)

You are absolutely correct, I should have called you guys before posting this up on here and for that, I apologize. I edited the title of this thread because I did find an issue, it was a relay that was not fully seated in the connector. Not sure how I missed it, or maybe it happened during the install, not sure. But it is working OK for now. The high speed still Seems to draw a very heavy current, especially at idle. I have the upgraded DR244 alternator but still have the factory sized ground/power wires.

I also got your voicemail on Friday but it was too late for me to reach you. I am still interested in converting the harness to a 2 wire setup, matter of fact I have already changed the tune to accept fan 2 turn on with the pin 33 instead of auto-recirc.

I do tend to agree with 2xLS1 though, you should consider retiring this 1 wire design. Had I known i could have used the 2 wire setup and it was so easy to change the pin 33 assignment within the tune file, I would have just ordered the 2 wire harness. Like I explained above, people living in colder climates don't want the high speed fan coming on in the middle of winter when they are trying to defrost the windshield. It will make it nearly impossible to reach operating temps.

Mike