LS wiring harness guidence needed
 

Guys my Brother and I are working on a C-10 truck and we are putting in a LQ4 motor and 4l80 transmission in the truck. We have all components including the computer, throttle module and all wiring out of a early 2007 2500HD. We are at the stage that we need to address the wiring and computers. what is the best way to go regarding the wiring harness and computer for my ls motor. Should we buy all new or send off the existing wiring and computer and have it re flashed. We are not sure if the aftermarket world has put out cost effective products or is it still more effective to send this stuff off.

Also we are putting on a ls2 intake

I've never used the truck parts but when I approached my build it seemed to me the computer and all the other parts don't know the difference if it's in a 1962 or a 2002 car. Any tuner can adjust the speedo and eliminate the anti theift stuff for you and the rest of the system couldn't care less. So I didn't see any value in buying a new aftermarket harness for it when I had the factory one with the engine it belongs to and I know they work together.

I found it very helpful to have factory shop manuals for my donor. About 80% of the book is useless but that other 20% is priceless. I just used the diagrams in the book to hook up the power, ground and the other 20 wires from the car to the harness and it worked fine. But again I did a 2002 Camaro into a 1996 Miata so I could be totally out to lunch with the system you have and what you are doing.

We have found that PSI makes a great harness and sends out a computer flashed so you can get it up and running. The fuse box is simple to hook up and the instructions are very well detailed. Price is also very reasonable-chris

^ x2 Chris.

x3. They have great customer service, and a great product. I sold my old harness on eBay and picked a new one up from PSI.

PSI had the PCM I needed so I called and ordered it along with a harness, too good of a deal to pass up, nice people too.

I ordered it on 5/2/14 and they were supposed to ship it 5/7/14 but never sent me a tracking number so I call up there and they said they would check on my order and call me back. Its been a few days and still havent heard back from them. Should I be worried or is it average to take a while for turnaround time? Its a basic vortec harness, nothing special. I dont mind it taking another week or two than planned I would just like to know, I was going to try to drive it to goodguys this weekend.

Their products are great but their service can improve a bit. I've left messages before and they never called back. Just stay on them.

Thanks for the feedback. Ill give them a call again tomorrow. I dont want to bother them and pull them off production to talk on the phone but would like to know whats going on.

PSI is a very good company to work with they have great customenr service, the harness was a little tight in some spots but we made it work. With swaping to the LS2 intake a couple of ways to shave some time and money, use speed density tuning to elminate the MAF and O2 sensors, and all you have is the IAT sensor to plumb into the CAI. I spent alot of time ensuring the 02 sensors matched the harness along with the other parts. My tuner deleted most of the functions to get my HP and TQ levels where I needed them. Good luck with your build!

My PSI harness, PCM came in. Communication not great but product is just fine and thats all that matters. MAF plug a little tight but no biggie.