Helpful tips for removing wiring harnesses-78 280Z

[One Way]

The teardown slowly continues.  Gameplan is a dip or blast of the stripped down car so I want to remove all the harnesses.  The harnesses are a huge improvement over the wiring I found in my 68 Datsun 2000 roadster, but also much more complicated.  So far it looks like the large plugs are self explanatory and the smaller ones ( contrary to the 68 roadster) are actually color coordinated.  I will be taking careful notes and diagrams, and tagging all the ends of the wires but am looking for any helpful tips some of you Z experts may have learned in your years of experience.  As a whole the harnesses look very good-RR tail light wiring is damaged-appears to have been chewed through during the many years this vehicle was neglected and parked- and I will eventually clean up the harnesses when and if the reassembly process begins.  I am finding a bit more structural damage the more the vehicle has been torn down but I will remain optimistic about the project.  Suggestions for removal, cleaning, retaping, rerouting, etc.will be greatly appreciated.  Thanks, John-Lugoff, SC.

 

[rossiz]

if you haven't yet, download the fsm - it has some great diagrams outlining the various harnesses that will help you identify them and their routing.

[sweatybetty]

sell it to someone and buy an aftermarket universal harness. my 2 cents

[Mark Maras]

 If you're going to pull the main harness from the area above the right rear tire, attach a line (fish tape) to the end first. You'll have a way to pull the harness back thru the body when you reassemble it.

[grannyknot]

When you do finally get to the wiring harness give yourself lots of time, 2days to week depending on how much work it needs.

Lay it out on the floor in the shape it normally is when it's installed. You will want to remove all the wrap so you can check for burn throughs, nicks, previous modifications and connectors that need replacing. I found it very helpful after removing the wrap to bracket with a tie wrap on either side of the harness where a wiring lead left the main harness. You don't need to pull them tight but just enough to mark location where the wires come out so when you are recovering the harness you end up with the same length of wire coming out at the right spot. There is nothing worse then doing a perfect wrapping job, go to install the harness and find it doesn't fit. Then you have  do a cut and patch job on the spot or redo all of your work again.

You will be amazed at how much crap can get inside that wrap after 30-40 yrs and it is not uncommon to find 5-6 wires melted together with only microns of plastic insulating them from each other. If part of a 16 gauge wire needs replacing I like to pull the entire length and replace it with 14 ga., same with the lighting harness, I have found it a good practice to up size all of those wires.

Also, before doing the final wrap I have found it useful to add an additional 4-5 wires into the harness that will run from the engine bay into the cab and a few from the cab to the back of the car. Clearly mark them as dormant wires so when in the future you want to add some electrical thingy your wires are already there waiting and you won't have to have jerry-rigged  looking wires poking out running across the engine bay.

Chris

[One Way]

As usual, thanks for the tips.  I always go to the factory service manual to get a general idea of how any of the systems work, and thought the section on the harnesses was pretty good, but not too much info on removal or restoration of the harnesses.  I am quite amazed on how good the harnesses look on this car but as stated before you might find some 

problems underneath the tape wrap and other issues when I actually get the whole harnesses pulled out.  Thanks again, John.  I never like unwrapping all that factory tape and my wrap jobs never seem to come out as good as the factory.  I also like to cover the tape wrap with split wire loom for added protection and appearance.  Not sure if that is the best approach but we will see when we get that far into the project.

[Zed Head]

One major difficulty is removing the colored connectors from the white plastic framework by the fusebox.  It looks like Nissan meant for them to go in but never come out.  I tried when I had a 78 parts car but couldn't come up with a method.  I think I've seen one out on the internet somewhere though.  

[Captain Obvious]

What Zed said.

For those of you who have not had the pleasure... Getting the connector shells out of the holder block is a royal PITA. With enough time, contortions, and small thin bladed instruments, I succeeded at getting mine apart, but it was a frustrating ordeal.

Something so seemingly simple and ordinary, well.... isn't.

So if you're planning to pull the main engine compartment harness out of the car, be ready to deal with that.

[One Way]

Thanks for the heads up on the connector housing near the fuse box.  Captain Obvious certainly got it right.  That project is the type the Lord sends our way to help us build patience-"Knowing this, that tribulation brings about patience"  Romans 5:3-It took a good 45 minutes of wiggling, jiggling, no cursing, and a handful of tiny screwdrivers to get those connectors out of the block.  All without breaking any of the tabs or connectors.  Obviously designed to be a one time process only by Datsun engineers.  I have removed the entire engine room harness-found only 1 broken wire-connector to the switch that goes into the bell housing.  After lunch I hope to get the EFI or interior harness out, maybe even both.  Where is a good source to get the factory style plastic clips used to secure the harnesses?  Most of mine were very brittle and cracked.  Thanks again-John-Lugoff, SC.

[One Way]

Successful removal of all 3 main harnesses today.  I will definitely need lots of new plastic mounting clips when ready to reassemble.  The EFI harness will also need some help.  All of the injector connectors were very brittle.  A few of them just kind of crumbled with slight pressure and several of them were full of green corrosion.  The rubber sealing boots were mostly cracked or very brittle too.  All in all a major step in the tear down process.  Thanks for all the helpful info, John-Lugoff, SC

[rcb280z]

My hats off to you for getting the "engine room" harness out! As mentioned above it was a Royal PITA! I did mine 10 years ago and swore never again. 

There are several injector connectors available and opinions to go along with. I used these and love them.

Mouse over image to zoom

Have one to sell? Sell now

A10B1F1 Wire Harness Connector Repair Kit AFM TPS Fuel Injectors For Datsun 280z

I don't buy from ebay often but decided to give these a try and all is good. You'll find something simular if not these.

[rcb280z]

Guess I should add that the main reason I like them is the ease of removal when you need to replace an injector or....... The spring clips make it simple. No hunting around for the original clips if you happen to drop one or one goes flying across the room.