I have a complete harness for a 84 gsl the whole interior wires and all and I am planning in putting that in the 79 I got p. I know I will have to cut some wires and mix them with a broken 79 harness I got for the interior. Has this ever been done?

 

You may want to start accumulating posts and get to the 1st gen specific section where there is a vast amount of info awaiting you.( Rules at top of the NEW section tell you how to gain 6 important needed posts,maybe more).
Although you may get some rough answers in this section,it is a "mixed bag" of car series and owners so if you get to your own specific section the answers come more quickly by guys that actually have your series of car.

 

Wat do you mean gain 6 important post

 

it's been done, but most of the time it was people basically swapping interiors because they wanted the S3 look/updates. if you're looking to fix your '79 harness with '84, i have a feeling you may be on a counter-intuitive endeavor (my thought).

he means build your posts up the right way (using the stickies gives you 6) so you can get access to the rest of the board.

 

If you are planing to swap new wiring i would strongly recommend using a new one. I have found when trying rewire new or old components with mine that just moving the wires caused a open in the harness . Copper gets brittle . Not only that when i decided to install a hot rod harness it clean up everything with more reliability .

 

+1

check this out:
TurboII swap Project: Complete vehicle reqwiring part 1: chassis - RX7Club.com

 

The wire harness I got 84 is new no cuts or nothing but the old 79 is cut up. I got the car with it...

 

If you have seen the harness then you know what your getting into . You should have wiring diagrams of both years while doing it . When i did mine i found a lot of factory splicing . The manufacturers dont care to much about servicing or adding aftermarket equipment to your harness. So if you are to do that on top of the factory harness you will need to install more relays and extra wiring to handle it . Im talking extreme but I'am no slouch when it comes to wiring and there is so much wasted time when all you need is a aftermarket harness which are built to expand and can handle the loads and so much easier . The hardest part was the pop up head lights . Just make suer you keep the bucket switch . I lost mine and ended up putting it in a toggle . Then found it after it was all done ;/. Just my opinion . I would at least look into it and under your dash. That harness is nasty ! Plan to do it once .