[MarkZ]

I am thinking about doing the Turbo thing to my 72 That already has a F-54 and a p90a.The main thing that hs me worried is the wiring harness swap.Is it as much of a pain as it seems? I can do this type of work if it not major tear the car apart,swearfor a week, throw your tools across the shop type of job.What year harness do i need?I would love to hear from anyone who has done this.I checked the archives under "Wiring Harness"Didnt really see a how to post.Anyone know if someone has a site dealing with this swap?


Thanks Mark

 

[Sparky]

it depends....

on what harness you swap too. the harness in my 240 was toast....but the one in my 280 parts car was great....so i just swapped the entire thing over....bumper to bumper...now that might be a little more involved than what you would like to do...cause let me tell you this right now....no matter what kind of swap you do....LABEL LABEL LABEL!!!!!!...I thought that my swap would take me about four days....well...after taking the dash out...i decieded to swap gauges as well...and paint the firewall...and soundproof it, and add a heat shield...well the wire is in but ive had to remove it several times because of "while im in here i might as well" type changes.

there are 6(?) wires on my 280 Z injection so its really not that hard to hook up if you wanted to keep your 240 main harness. youve got a ignition trigger wire, a power on wire, a constant on wire, a ground...and some others....ill look through my diagram if you really want to know what they do (just email me). all in all its not to hard...just be sure to have some (alot ) of automotive electrical system knowledge...some common sense..a test light, a multimeter...and time....just take your time. i would allow 1 week min. for the harness swap and testing time.
dont forget about the hole saw so you can route the wires.

anywho.

good luck

laterZ

-Sparky
72 240ZT

 

[DAVE H]

I put a 83 turbo engine into an 82 rust free body. Complete wiring harness and dash change except for the heater/ac. I kept the manual heater/ac from the 82.
It takes a lot more than a week to do it right and most of my stuff matched right up. Patience is the rule when attempting something like this. Label everything good luck to you.

 

[escanlon]

I would heartily recommend that if you have access to a digital camera or a polaroid and can afford the film to take pictures of the critical hookups!

The FSM and the OLD Clymer's manual give you references to where the connectors and the loose wires hook up to, but even they aren't complete.

When I swapped out the dash wiring harness on my 240Z AT, I inadvertently got from the boneyard a harness for a manual. Pretty much everything hooked up, EXCEPT for the kickdown switch and some loose cables that go to the center column area. Luckily I had some photos that allowed me to figure it out, unfortunately, the photos did not address the wiring specifically, but just showed it. Talk about a major PITA.

Remember, as you label, the NEW harness won't have all your corresponding labels, so you'll have to check color coding on the wires, and yes, believe it or not, sometimes at the connector the wire color changes.

 

[Sean73]

I've been contemplating the turbo swap myself. My question is, why not just keep the 240Z wiring harness, then mount all of the turbo/FI engine management hardware in the engine compartment? I don't see why the whole 240Z wiring harness needs to be replaced.

 

[escanlon]

Differences in Wire Harnesses

Because the 240 did not have any kind of computer, the wiring harness for it will not have any allocation for plugging in a turbo or fuel injection computer or any of the other things that go along with it.

If you had a wiring schematic for both, and took the time to investigate the similarities / differences then you could determine what parts to swap and what parts to ignore.

However, having already had the fun of trying to trace down two wires that weren't on the new harness that are needed for an automatic, I can tell you that it's best to get the identical harness to swap to, or in the case of what he's considering, to get the whole thing and "re-wire" the car rather than trying to splice the new equipment in.

This will save him hours of frustration and will also ensure that the wires go to where they're supposed to. Yes there will be some components that he'll have to change or change the connector that attaches to it, but far less than having to figure out where to hook up the computer to, or any of the other things for the FI/Turbo.

FWIW

 

[MarkZ]

Thanks for the replys,If i did try this swap i would for sure take your advice escanlon and label and pic.I was hoping to get some responses along sean72s line of thinking .Couldnt you adapt a aftermarket brain and leave existing harness.I just know i would regret tearing out all that wire!


Thanks again
Mark

 

[escanlon]

Sorry for the delay in posting to your question.

As far as adapting an aftermarket brain and plugging it into the wiring harness, you could probably do just that and get it to work. However, I must caution you on a couple things.

First, the 240 cars were not only NOTORIOUS, but also completely INFAMOUS for melting their fuse boxes and other wiring. As it was, the wiring is RIVETED to the fuse box, and I've tried soldering some of these and only ended up with melted plastic around the connection. Adding wire and other current drawing devices seems to me like putting 3 overweight big guys in a boat rated for 4 "normal" sized guys, yes TECHNICALLY you haven't overloaded it cause only 3 guys are in there, but you have exceeded the weight limitation, go ahead and fish, I'll wait on shore.

Second, are you good and I mean REALLY good at reading schematics? If not, then why put yourself through the headache of trying to figure out where to splice into the old harness, when the engineers figured it out for you on a later harness.
Yes, removing the dash, and other parts that hide where the wiring harness was snaked through may seem like a lot of trouble, but believe me, it isn't all that hard.

I've personally replaced the complete wiring harness on the back of my dash. In so doing I eliminated several "improvements" by the prior owner that resulted in several short circuits, a melted fuse box and also a shorted ammeter (try that one out for size) as well as a burned out accessory relay. Now, the lights on the dash light, they dim, the heater fan works, the pre-heater on the heater box works, the tach works again, the turn signals show the proper side, the brake warning light operates properly, the horn works, the CLOCK works, and most important of all, the battery actually maintains its charge. Was it a PITA, yes, would rather have been driving it. Would I do it again, you bet! Now I can access either the Chilton's, Hayne's, FSM, Clymer's or other wiring diagram and know exactly where and what wires to work with to add in the fog lamps to the actual circuit included in the wiring harness.

So let's face it, unless you are incredibly methodically anal about annotating each and EVERY connection for your aftermarket brains, if you have any problems, you will be starting from close to ground zero every time you have a problem. Additionally, going to a mechanic? Only if you've been there before and he knows that it used to work and doesn't question your splicing into it. It is much easier to say, it's a 71 with a 78 wiring harness and turbo, so use the 78 wiring schematic and tune up specs.

Sorry for the ranting, but I think you'll learn more about your car by doing the harness swap than trying to splice in something. In fact, it might even save you a headache or two.

FWIW
Enrique Scanlon
eM: [email protected]