So the electrical saga continues with my z...

I have a 1978 280z and it recently developed a tendency to turn itself off when I'm driving. It started with it just turning off when shifting into reverse but has evolved into turning off with the right blinker once (I could hear the a relay in the passenger foot well clicking on and off with the blinker) and also just randomly while driving. Today it died in my neighborhood before i could leave and wouldn't turn back on until I jiggled the main wiring harness around. Because of all of this I suspect two wires shorted together since the turn signals and reverse are on the same circuit and removing the fuse for them fixes the problem but if someone could help me track down where in the harness i should be looking and what wire to the main ignition relay or other relay that would kill the car might cause this.

Probably wires in steering column that connect to the ignition key assembly.

2 hours ago, 240260280 said:

Probably wires in steering column that connect to the ignition key assembly.

I'll check there but the turning off when going into reverse has me thinking it would be over where those wires run

With the behavior you described, it's likely one of two scenarios.

1. There is a problem, possibly with the ignition switch, and what you perceive as triggering events are just coincidence.
2. A previous owner has hacked into the wiring to "fix" problems.

You might want to pull off the steering column cover and start looking for splices.

I fixed a splice I didn't like on the ignition wire and I checked and have power to the coil (last thing on the ignition wire I think?). The car still won't start though. I have no dash lights like the parking brake light and my fuel pump won't turn on.

Let me be frank here...

You'll need to supply a LOT more information to get decent responses (and not have someone posting pictures from The Naked Gun).

You found a splice you didn't like, but you don't say what wire was spliced (the colors are important), how it was spliced, or where the foreign wire went to. That splice may have been one of those "fixes" a previous owner did to work around a problem instead of diagnosing it properly. 

It is challenging to track the history of the issues. When did each issue start? You added things about the dash light and fuel pump. When did you remove the splice?

We cannot see your car, so you have to paint a picture with words (and post photos). If you have a half decent camera on your cell phone, there's no excuse for posting without photos.

Could it be loss of ground? He has power at the coil but it's an efi car.

Does the starter spin the engine? ie Turnover?

Does it fire at all when it spins?

Will it fire if you shoot starter fluid into it?

Sorry for not providing info but the splice was on the black with white stripe (the ignition wire). The splice was my fault from installing a relay for a light I only wanted on with ignition so it went to a switch that currently does nothing. I spliced it with a waterproof heat shrink crimp but it was loose and I was able to pull one of the wire off. Again my fault. I then soldered the wires back together and covered them with heatshrink this morning. The issue of the dash lights and fuel pump not work has been with the car ever since I put it back together after rust and paint work. This is my first run with redoing a car so I didn't pull the wiring harness before it went to the shop that did the aforementioned rust and paint work which I regret. I will post pictures when I get home.

 

If there is anything else I should/can provide just let me know.

Edited July 26, 20195 yr by Usain_Boat

50 minutes ago, Patcon said:

Could it be loss of ground? He has power at the coil but it's an efi car.

Does the starter spin the engine? ie Turnover?

Does it fire at all when it spins?

Will it fire if you shoot starter fluid into it?

The starter spins but the engine doesn't fire at all when it is turning over. I haven't checked with starter fluid but with the wire pulled off the starter solenoid I do not hear the fuel pump so I will check for spark and starter fluid this evening.

Mind you that I'm probably not the first one to come to with electrical issues, but back to what @SteveJ mentioned, did you check your ignition switch?  It's a fairly inexpensive part and should be easy to do if you already have the clamshell off.

1 hour ago, gwri8 said:

Mind you that I'm probably not the first one to come to with electrical issues, but back to what @SteveJ mentioned, did you check your ignition switch?  It's a fairly inexpensive part and should be easy to do if you already have the clamshell off.

Is it fine to just check with a multimeter? Or should I buy a back up.

Multi meter should be able to handle the diagnosis