I've yanked out the mpfi v6, and now I'm trying to get the wiring inside the car for the TPI v8 ready. I've got a painless TPI wiring harness. It doesn't seem to use many, if any, of the original wires already under the dash....so what should I do? The new harness even replaces the ALDL connector! There is a check-engine light with the new harness, too. Does that mean the stock one won't work anymore? Should I cut out the old wires to make room for the new ones, or just cram the new ones in with the old ones, disconnecting the old ones where I have to?

 

Any info would be good, I'm getting ready to do that same exact swap. The check engine light might be there if your chip is programmed for use with a smog pump and you didn't install a smog pump though.

 

Hey proximo what all came with the harness? is it for the engine and dash as well? You should only need the engine part of it, as the dash harness should support the TPI without many, if any problems.

 

the harness is a two-part harness...engine/dash sections. The factory one had mostly the same engine connectors, but the dash sections are different. For the factory harness, it has the ECM connectors and then two small connectors that attach it to all of the under dash wiring. The painless harness has all the under dash wiring of its own...it doesn't hook into the factory wiring. That's why I wanted to know if I should pull all the factory under-dash wires out, or leave them and cram the painless wiring harness in with them. I'm leaning toward pulling them out because I want a clean under-dash area. Not a spider-web jumble.

As for information, I'm writing a webpage as I go along...so I'll leave the address on the boards when I'm finished.

 

I used one of their harnesses for my Lt1 swap. The harness isn't vehicle specfic....in other words, it is probably set up to install a TPI motor in any vehicle. The check engine light is there in case you didn't have one on a custom job. You can hook the wires for it from the Painless harness to the factory light if you prefer. Also, the new ALDL connector will bolt into the old location where the original one is. As for the dash wires, you should just have to tap into a few underneath there. Call them if you run into trouble. They are very helpful.