zapp109

iTrader: (13)

Curious if anyone had any good info/links on wiring? I have a 87 Notch already done by some hackjob, the harness thats in the car now i belive is out of a trans am, so i got a new PSI harness for T56 since im running a turbo400, and I want to start over and do this right cus its the biggest mess of wires and looks like Shhh.. I did a quick search on here but theres 900000 mustang wiring topics but nothing what im looking for.. Any help good write ups is what im looking for..

Thanks
Craig

itsslow98

iTrader: (18)

If you want it to look good and be done right and easy, pay 450 and have speartech rework the stock harness.

There is some wiring info in the sticky at the top of this section in the budget build 1500 thread.

ebk06

iTrader: (5)

Youre not going to find a write up on how to wire your cars pcm if thats what youre looking for. Its simply too much work to post up and everyones application is different. You have two options, send your harness to someone to rework it for you or find the wiring diagram for the year harness you have and rework it yourself. There are no shortcuts for this.

zipster

iTrader: (5)

I used the stock wiring on the Mustang harness and tied what I needed into the LSx harness. My harness was from a LQ4 Silverado and I used LT1swap.com for the info for the Ls harness. I just unpinned everything and rerouted it. Then added wire to the short ones. Solder and heat shrink. I removed enough wires from the harness that I did not need to buy wire to add to the short wires. It can look confusing, but LT1swap.com was the key to the LSx harness. Take your time and lay it out on the engine. My engine was on the stand so it was easy.

zapp109

iTrader: (13)

well this may be easier than i thought since its already done and in the car.. My new wiring harness has its own diagram telling me what everything is, I was just curious on splicing into the original (mustang) harness and what all really needed to be done. I am running all aftermarket gauges (no mustang gauges), one of the main reasons i went and got a new harness was because we went to tune the car the day I got it and the damn plug to read the computer wasnt working so all we could do was a flash tune.

ebk06

iTrader: (5)

To add to zipsters comment. The factory harness on the mustangs can be used for the lights and gauges. Dont cut that out or modify it.

Now modifying the ls harness wont be done overnight and requires lots of looking over diagrams. It takes time so dont rush or you'll be kicking yourself.

ebk06

iTrader: (5)

Looks like we posted at the same time so let me try and help out here. My mustang has all aftermarket gauges. The only thing you need to worry about is finding the speedo and tach signal wires. oil pressure, volts, water temp, dont need to be connected to the harness. Fuel level only needs the signal wire as well. Like I said check my build thread and look over it. I show how to wire the aftermarket fuel level sender onto the car.

Also I posted a diagram of the factory plugs for the factory cluster and it shows what wires go to where to simplify wiring. It shows the turn signals, high beam, and brake lights for the dash.

zapp109

iTrader: (13)

Yea ill check it out, honestly this new PSI harness is really well laid out and clean with a nice diagram so this shouldnt be too bad. Maybe ill do my own little write up for people and document what i actually have to do. Also I definitely need to check my signal wire for gas gauge cause mine fluctuates also could be the sending unit in the tank going bad..