Jump to content
HybridZ

Advice on rewiring car


Recommended Posts

Hi guys,

I have a 1976 280z.  I am new to Datsuns but have done an LS swap in a 60s muscle car (that had much less wiring).

 

I am putting a 5.3 LS/t56.  I want to rewire the car.  I will be trashing the stock engine wiring harness and likely running a Holley standalone with harness.  I will be replacing all factory gauges with aftermarket.    The biggest challenge seems to be the ignition and steering column. 

 

I have read that some people like putting in an EZ wire universal kit.

For people that have done a motor swap and rewire before, did you just trash the factory junction block and connectors?    Or just use a couple of them?  

 

Any other general advice?

 

Thanks

Joe

Link to comment
Share on other sites

Honestly the biggest factor is your budget.  I just finished doing what you describe, wiring the entire car as well as the harness for the LS3.  I used a PDM, which made things much simpler and more flexible.  But there is no denying that PDMs are expensive.  If you go the "mil-spec" route with the wiring....that is another significant expenditure.

 

Any way you slice it, this will be a fiddly and time consuming job...but I imagine you know that...

Link to comment
Share on other sites

I am not an electrical guy at all in reality.  So take everything I say with that in mind.  A lot of people are way better at this than I am.  

 

I/we did a stand alone EZ for the chassis, having used just about every other manufacturer in the past, Haywire, Painless, Ron Francis, AAW, and I squared.  It was ok some of the wires were poorly marked and most are marked only at the ends not all the way along like Painless. We tried to put it in the same spot as the factory fuse box, I would not do that again, put it on driver side by clutch pedal.  Then I would put a new hole in the firewall for all the front EZ harness. we went all on the pass side for everything. EZ, LS and all.  The worst part is wiring all the switches.  Ignition was easy, headlights high/low not so easy, never even tried the flashers, signals work and were not bad.  Wipers/headlights are still not 100% right.  The wipers we got to work, then I found out the wipers don't work with headlights on (law in my state is wipers on = headlights on), the wipers lose their ground when headlights come on.  Work on park but not headlights (found that out on a rainy day, RainX is great).  Still have not figured it all the little things but everything now works, some not perfectly but works.  Wipers can always be turned on (not ignition fed) and only park manually.  We tied the rest of the EZ into the Datsun wiring at the passenger foot well for everything as it was easier than running the new.  It was in good shape also.  

 

On the LS side we used the guys from Arkansas (eBay) and they did the diet on the Donor harness.  We ran the wires for 12V constant, 12 switched, fuel pump, fan etc. all from their supplied fuse and or relay block.  We even used the LS computer to run the AC.  Speed hut, tach and speedo, Datsun for everything else.  Clock still works, LOL.  

 

As said above even if done by you it takes time, a lot of it.  I had the Dash and harness out of the car and on the bench with a column and switches for a month figuring it all out.  I had a buddy who is pretty good electrically, (jag owner) help finish the job as I was mentally spent.  So far no issues have come up except for what is listed above.  My wife even drives the car.  AC heat etc. all work.   About as honest an answer as I can give HTH, Richard.  

Link to comment
Share on other sites

I've done this a couple of times and I would suggest not to throw out the stock wiring harness so fast, it is made of good quality wire and usually just needs having the connectors cleaned. I usually end up splicing the stock harness and the engine management harness into one.

Link to comment
Share on other sites

Depending on how many electronics your car is going to be reusing, I didn't find it too bad to just get rid of everything except the lights from the old harness and then make wires for everything new. Although I don't have many accessories installed in mine. I believe there is a color wiring diagram available for the 76 as well that should make it easier to dig through it.

 

 

 

Link to comment
Share on other sites

I finished mine recently. I thought the hardest part was figuring out the wiring for the steering column combo switch. That the headlights are negative interior didn’t help things but I just reversed that and ran the power through the switch. 
 

Getting one of those laminated wiring diagrams for your year car will really help as well. 

Link to comment
Share on other sites

6 hours ago, fusion said:

Joe, would you be willing to share how you wired the column?  That looks like the biggest headache by far!

 

I only used the turn signal/high/low beam switch on mine.  I melted the solder and removed all the OEM wiring.  It's pretty simple to figure out what does what....just put the switches in their "on" positions one at a time, and use an OHM meter to see where continuity exists between which solder terminals.  There is one ground terminal, and when switched "on", the other terminals are connected to ground.  One you have it all sorted, re-solder wires in whatever colors make sense to you.

 

It can be a little tricky to wire the wipers and get them to "park", but there are several tutorials online for various configurations.

 

The biggest headache is wiring the LS3, just because of the vast number of wires needed.  It can be confusing.  You know the wires to the electronic throttle and the accelerator pedal need to be shielded and the shield grounded, right?  Also, the resistance of these wires needs to be correct (as low as possible) or the throttle won't work properly....

Link to comment
Share on other sites

13 hours ago, Ironhead said:

 

I only used the turn signal/high/low beam switch on mine.  I melted the solder and removed all the OEM wiring.  It's pretty simple to figure out what does what....just put the switches in their "on" positions one at a time, and use an OHM meter to see where continuity exists between which solder terminals.  There is one ground terminal, and when switched "on", the other terminals are connected to ground.  One you have it all sorted, re-solder wires in whatever colors make sense to you.

 

It can be a little tricky to wire the wipers and get them to "park", but there are several tutorials online for various configurations.

 

The biggest headache is wiring the LS3, just because of the vast number of wires needed.  It can be confusing.  You know the wires to the electronic throttle and the accelerator pedal need to be shielded and the shield grounded, right?  Also, the resistance of these wires needs to be correct (as low as possible) or the throttle won't work properly....

Did you use a different ignition module?  If so, where did you mount it?

 

Also, good advice on the LS wiring.  I am planning on using a Holley standalone, so I'll be using their harness.

Link to comment
Share on other sites

  • 1 month later...

Steering column wiring

Hope this helps!

 

Z Wiring Harness Main Color/Stripe Color ----> Main Color/Stripe Color Painless # Description

Left Signal post White/Black ------------> Lt Blue 949 Left Rear Turn
Left Signal post White/Black ------------> Yellow 926 Left Front Turn
Right Signal post White/Red ------------> Blue 948 Right Rear Turn
Right Signal post White/Red ------------> Green 926 Right Front Turn
Signal Center Post Green ------------> Black 953 Flasher
Head Light Power Red (heavy gauge) ------------> Red/Black 925 HL 12v
Head Light Power 2 Green ------------> Orange 959 HL 12v
High Beam post Red/Yellow ------------> Light Green 908 High Beam
Low Beam post Red/White ------------> Tan 909 Low Beam
Dimmer center post White/Red ------------> Blue/Yellow 907 High Low switch
Running Lights switch Green/White ------------> Brown 929 Tail Lights
Running Lights switch Green/White ------------> Brown 927 Front Park Lights
Running Lights switch Green/White ------------> Brown 930 Instrument Lights

Link to comment
Share on other sites

  • 4 months later...
On 11/4/2019 at 6:49 AM, Richard Oben said:

Speed hut, tach and speedo

Not to jump into this thread and pull it from its origins...Has anyone pulled the old fuse box out in conjunction with an LS swap.  I have my LS wiring ready to connect the ignition wiring. I gutted the original body harness to the necessities (lights, horn, etc).  Then decided to go ahead and upgrade to the blue sea fuse box 12 circuit with positive and negative posts.  The problem is configuring the old 5 positive wires to 14 negative switches.  I can't seem to get any power to the switches.  Any help would be appreciated.  

Link to comment
Share on other sites

Can't really help, but remember the old set up was power the switch and then run it through the fuse box to lights or whatever.  Now it is power the switch from the fuse box and then the lights or whatever  The old stuff was just a small step up from British.  Richard 

Link to comment
Share on other sites

  • 3 months later...
On 11/3/2019 at 5:01 PM, fusion said:

Hi guys,

I have a 1976 280z.  I am new to Datsuns but have done an LS swap in a 60s muscle car (that had much less wiring).

 

I am putting a 5.3 LS/t56.  I want to rewire the car.  I will be trashing the stock engine wiring harness and likely running a Holley standalone with harness.  I will be replacing all factory gauges with aftermarket.    The biggest challenge seems to be the ignition and steering column. 

 

I have read that some people like putting in an EZ wire universal kit.

For people that have done a motor swap and rewire before, did you just trash the factory junction block and connectors?    Or just use a couple of them?  

 

Any other general advice?

 

Thanks

Joe

 

Joe,

 

Did you end up getting the Holley Terminator X harness? Just wondering how you hooked it up and what did you have to splice into it. Where did you route it thru, passenger or driver and location of mount. Thank you. 

 

Alan

Link to comment
Share on other sites

18 hours ago, fusion said:

Hi Alan,

I haven't gotten that far yet, still working on the engine.  I hope to get to it this winter.

 

Joe

 

Cool, thank you. I have a harness and was hoping you could shed some light. I'll definitely have my hands full this winter.

 

Alan

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...