OK, I am going to be putting an Si motor into my DX and originally was just going to convert my DX harness to run the Si motor. I was going to do a complete Si harness swap but decided that I would just convert it so I didnt have to mess with pulling out the dash but I ran into another problem my heater core went bad!! So my question is since I have to pull out the dash for the heater core anyway should I go ahead and do the complete under dash harness swap or should i stick with my original plan and upgrade the DX? I want to know if it is that hard once you have the dash removed to swap the harnesses? I just figured that I would go ahead and do the swap and heater core at the same time then my car is only sitting once. Sure it may be for longer but better than more than once. So how many of you out there have replaced your under dash harness and was it that bad?? I thought it wouldnt be that bad once I have the dash out and everything and plus it would then make it easier for me to switch the pedals (doing a auto to manual swap also). So what do you guys think?? Do the whole harness swap when doing everything else or just do the pedals and the heater core with the dash out and then upgrade the DX? Thanks for the help!!!!

 

the dash is easy to pull out, just remember theres bolts under the hood by the heater valve that hold in your heater box. I would do the si harness if I had the dash out already. its not that hard, just unplug everthing and pull it out. you'll have to disconnect the wires from your headlights and bumper lights and feed all those wires thru the firewall, but it will be a much nicer job, and shouldn't take that long. I converted the harness on my wagon but will be changing it out as soon as I find an ex underdash harness to swap it with.

 

If you are going to do a MPFI swap its much easier to use you DX engine harness on the Si engine than swapping the whole harness. The harness that plugs into you ECU actually runs up to your headlights and itno you doors. Trust me, I've pulled one out before. Just use your DX harness. You only have to run four wires to the ECU and this takes no more then 10 minutes. Also with the Si engine you will need an injector resistor box and four fuel injectors.

 

Yeah I have everything I need for the swap (had an Si parts car) And I know that the harness runs all the way up front but I figured if I am doing the motor swap and pulling out the dash for the heater core that it wouldnt be that bad to swap everything especially with the motor and dash out. I pulled out the harness out of my Si so I know how much work it is but I was just looking at the fact that on top of the motor swap I also am doing the tranny swap so I would have to run wires to the motor for the reverse lights and have to jump the park switch so it will start if I did the complete harness swap I wouldnt have to worry about the reverse lights or jumping the park switch. Anyone else have their opinion on what to do?? Thanks.
And thanks to you both for your opinions they were very appreciated!!

 

bro just make the harness and keep the dx dash harness less hassle we make new harness' all the time

 

well while we are talking about dx engine harness does, any one have one for sale? I need one. If so e-mail me at dem22s@aol.com

 

I dont really see what the hassle is? I am going to have the dash out and also the engine out I kind of thought it would be smarter to do the harness swap since that will all be out and I wouldnt have to worry about my DX being an automatic then I will have all the wires I need and it will be basically like stock.

 

you will be much happier with the si harness in there, knowing its a factory harness and no stuff to deal with. if your dx harness was stick i'd say just modify it but since you're swapping to stick I'd definately put in the si one.

 

Thanks for all your help!!