Question about LS1 swap
 

I,m about to pull the motor and start picking up parts to do the swap. Im in process of selling the motor and tranny currently in it and my question is, Do I need to keep the engine harness from current motor to do the swap or only need the harness for the LS1 motor? Thank You

Re: Question about LS1 swap
 

LS1 engine needs the LS1 harness, but you may need to do a little bit of modification to the harness,

Re: Question about LS1 swap
 

Ok so I don't need the current harness and can sell it with the motor. All I need is the new ls1 harness. Thanks

Re: Question about LS1 swap
 

You need BOTH harnesses. Read pockets threads on the ls swap harness to understand what must be done. If you have a tune port car, you could be better off selling the TPI harness and using a TBI or v6 harness for the same year of your car. Bottom line is you still need a stock thirdgen harness to merge with the ls1 harness if you want a plug and play system when finished.

Depends upon what you mean by "engine harness". The stuff that goes to the ECM will not be needed for the LS swap. Things such as ignition power will be used.

Re: Question about LS1 swap
 

Right. You can ditch the left half of the bulkhead connector. I thinkit was the left half... The other side has power for the inside of the car and some other odds and ends. When I sold both my TPI motor and my current car's LG4 motor, I sent the main engine harness along with them.

The LS1 haness is almost standalone. There isnt much blending of the two really needed. Plenty of info on here, esp from Pocket, that will show you how to build the harness and modify whatever you have to.

J.

Re: Question about LS1 swap
 

There is a whole section of this site dedicated on "how to install a LSX'
If you are not sure about what harness you need, you should really read those stickies. Because you need to mate those harness together.

As some members have recommend pockets right up is real easy to follow, I used that to make my harness and was simple, just follow it step by step.

Re: Question about LS1 swap
 

At minimum, you need the thirdgen c100 connector, C207 connector, and the underwood HVAC connector from the factory harness. Sure you can get these plugs from a junkyard and wire them back in, no issues, but merging two harnesses together in my opinion would save time and be easier.