The Wiring Nightmare

[PRATORIAN007]

WELL, HERE WE GO.

I AM DOING A FAVOR FOR MY BROTHERS BOSS

HE HAS A 72 DATSUN 240Z

WE THINK THE MOTOR CAME FROM A 74 OR 75 Z

IF ANY ONE HAS A WIRE SCHEMATIC FOR THE UNDER HOOD & UNDER DASH IT WOULD BE A GREAT HELP.

THE ALTERNATOR IS NOT CHARGING THE BATTERY & THERE ARE SEVERAL BURNT WIRES UNDER THE DASH COMMING FROM THE UNDER HOOD HARNESS.

MY MAIN INTEREST IS FOR THE ATERNATOR WIRING.

THANKS

CAPT.HOTSOCKET@HOTMAIL.COM

[ktm]

Alternator

Wiring diagram (much too large to load the image):

http://members.cox.net/bomccoy/240Z_Wiring_Diagram.jpg

[JimmyZ]

The large white w/ red stripe runs through the AMP guage. (Under dash) I believe this is the same wire that is hooked to the alternator hot lead.

You've got some real problems it seems. (As in replace both harnesses) If you are trying to jury rig an electrical system for temp use then it may be easier to bypass the regulator with a manually switched field wire to the alternator. This is just the beginning because you would really need to make an entirely separate system if you wanted any lights, etc. There is a good chance that other wires will follow suit due to their proximity in the bundle.

Best to take pictures and unsheath the entire bundle and fix what has melted. (Engine cpt and under dash harnesses)

While my dash was out I had to fix a few of my wires as the insulation had begun to melt away. The funny thing was that I couldn't figure out why the wires had begun to melt. They weren't part of any of the usual suspects like the headlights or other high amperage carrying lines.

Hope this helps.

Jim

[Arne]

BTDT. If the wiring is botched and melted, the simplest solution (and the one I did on my yellow car) is to replace the bad sections of the wiring. Wiring harnesses for 240Zs have three main sections - the engine compartment, dash and rear body. The rear section rarely has big issues, but the dash and engine harnesses do. If you decide to go this route, do yourself a BIG favor and try to find harness sections from the same year at least, and preferably as close to the same build date as possible.

[Ramses]

I had to do the same thing with my '73. The problem that I see with yours is that there may be some issues with the different years for the motor and the car. If you dont want to cut the wires and you do want to have a clean transition between the car and the motor. It sounds like you have some major issues. I had to buy 6 wiring harnesses and merge them into 3 in order to get them to work.

Good luck

[JimmyZ]

What a coincidence! I had a great realization/lesson about my White wire with red stripe. Driving down the road I noticed the smell of burning wire so I shut down the car immediately. Turned out it was the WR wire to the fuse box. I had no lights or accesories on and the AMP guge read full charge. hmmmm..

After some consultation of the wiring diagram I decided to unplug the field wire from the alternator. The wire now stayed cool even with the lights, etc, on.

Hooked up the alternator and a voltmeter and found that I had a bad regulator (16+ volts) Replaced the regulator and no probs. Just need to fix the melted plastic connector now.

This might help here.

Jim

[ou812dam]

Wouldn't just be better to take the old one out and basically rebuild. lay the one out cut the connectors off only, get some new wires lay it out in the same manor clean the old connectors up and reuse them or buy new ones. i guess basically just use the old one as a blue print and for length and layout this way you can do one small section at a time!! I am thinking of doing this?:disappoin

[hls30.com]

Sounds like a case of tipping the battery in a turn and shoring the posative terminal to the hood(look for a burn mark on the hood in the area that would be above the battery with the hood closed.

I would just replace the harnes with one from the same year-too easy for theburnt wires to fuse all of that insulation together, and the burnt plastice produces some pretty nasty checmicals that will cause corrosion to start.

Will

[3RD STRIKE]

first i would like to say that i dont know every thing about the z,s im not familuar with yours, but i race the 280,s and the one i have was found in a field so it had every problem you can think of. i had this prob. w/mine. close to the battery there should be a small box with fusable links these are a prob.in the z,s. if your car has this box it is easy to test. the wires in this box are eithier burnt or corroded. your dash lights probably dont work or your tail lights dont work either. if this is true if you get charging prob. fixed it will fix the other probs. O.Kreplace the wires in the box with new ones. I recomend one size larger than stock. THIS IS BASED ON THE PROB. I HAD WITH MY 1980 280 zx.