Entire Car Rewire

[jeffball610]

I figured that upgrading the chassis wiring to something a little newer might be a good idea since I'll be wiring in a newer motor and ECU.

Is it a bad idea to grab a chassis harness from another model car and use the stock 510 end connectors on items like the taillights? I figure that being able to run a modern fuse panel and relays would be simpler than splicing into the old harness. I don't want the price tag of running a nice new unit like a Painless harness, but was wondering if this is a good idea or way too much work to make it worthwhile. I'm sure someone on here has done this or something similar and should have some good input. Is the old harness even worth saving?

[okayfine]

I figured that upgrading the chassis wiring to something a little newer might be a good idea since I'll be wiring in a newer motor and ECU.

Is it a bad idea to grab a chassis harness from another model car and use the stock 510 end connectors on items like the taillights?

Uh, are you just talking about using new(er) wire between the stock 510 switch and the stock 510 connector/bulb housing/whathaveyou? Because it's either that or that you want to use an entirely different car's harness and attempt to make it work in the 510.

I figure that being able to run a modern fuse panel and relays would be simpler than splicing into the old harness. I don't want the price tag of running a nice new unit like a Painless harness, but was wondering if this is a good idea or way too much work to make it worthwhile. I'm sure someone on here has done this or something similar and should have some good input. Is the old harness even worth saving?

It sounds like entirely too much work, work that will only introduce a hundred new failure points. You are looking to save money versus a Painless kit, however if you value your time you will lose attempting to run new wire to every switch, bulb, and connector in your car.

As to your last question - who knows if the old harness is even worth saving. Only you know, because you're the one looking at it. We can't see it, we don't know anything about it.

You could tell us.

Is the harness original to the car? Has it been hacked? Has it been modified? Do all the electrical systems work as they are supposed to?

The wiring harness in my car is original to the car, it hasn't been hacked, and has only been modified slightly. It works perfectly, with all systems functional. In my case, there's no reason to rewire the car just because the OE wiring is 40 years old.

Your mileage may vary.

[icehouse]

I had the same idea once Spent about 2 weeks after work wiring in the S13 chassis harness. I thought it would be an "upgrade"..... IMO it was a waist of time. I ended up ripping it out. By the time you go through and rip out every extra wire there are about 2 billion dead ends, the bulk head connector only had about 40% of the wires left if that. On top of that quite a few need to be lengthened or shortened.

Looking back it was a total waist of time, but I learned a ton getting that involved in the S13 harness. Even the S13 has very small wires for IMO biggish functions. So looking at the 510 wiring just makes me realize that the problem isn't small wires it's just 40 year old gauges, bulb sockets, and in the headlight case pore circuit design. I would still like to redo a 510 harness some day, but until I have about 3 months and know my way around sealed connectors I'm going to save that project.

Ben did it on his car and drives it. He runs a S13 column switches and cluster.

[jeffball610]

This is good info.

I was planning on just using new wires and the old connectors so that I wouldn't have to change out all of the 510 connections to things like taillights etc. As far as I know there are no issues with my 510 harness, I just thought that it might be an "upgrade" to use a newer wiring harness. I guess I could just wire in a modern fuse panel and update the circuit design in areas like the headlights as mentioned. The 510 wires do seem to be a thicker gauge than a modern wire anyway.

I don't know how often this subject might come into the head of a project builder, but after some thought, it won't likely do any good. The only "upgrade" I think that might be made is to the circuit design and using modern fuses and relays. Perhaps given the time and energy, it might be a good idea to update all things including wiper switches, column switches etc. But that seems like a lot of work for most of us with only a small gain in function or reliability.

If anyone else has opinions or first hand knowledge of doing something like this, let us know.

[banzai510(hainz)]

in areas like the headlights as mentioned

just run a H4 wire harness that use the stock wire(Outer passenger lamp plug in) as a trigger.

[okayfine]

just run a H4 wire harness that use the stock wire(Outer passenger lamp plug in) as a trigger.

This is what I do and recommend. I've bought a few different H4 harnesses over the years for my cars and never paid more than $15 off eBay.

Jeff, unless you have issues with the 510 wiring, I'd leave well enough along. With regards to your modern engine swap electronics, however, in the past I have acquired a blade fuse and relay box out of a modern Nissan to connect the ECU and new wiring. Later '80s and early '90s Nissans have 1x5 panels where you can fit a Nissan relay or a 3-fuse set of fuses. They're interchangable though the 5 spaces, and you can add a further 1x5 panel if you need more room. You can also print a label for the top cover of the panel box when you're done so you and future owners of your car know what's what.

[jeffball610]

You can also print a label for the top cover of the panel box when you're done so you and future owners of your car know what's what.

Future owners!? Never!