78 280z turns off with turn signal/reverse lights

[Zed Head]

45 minutes ago, Usain_Boat said:

Engine still died with the ignition relay bypassed.

This is actually a good thing.  Now you can look elsewhere for the source of the problem.

Try to determine if you're losing ignition power, fuel pump power, or both.  That will be a clue.

[240260280]

Try disconnecting the connectors 1 at a time to the lights switch/wiper switch in the steering column and see which one causes the problem. Watch out for the power cables from shorting.

[Usain_Boat]

Well I've already traced power for those circuits. I lose power at the fuel pump relay output (the relay clicks off) and I also know I lose power on the wire that provides power to the solenoids in the fuel pump control relay and fuel pump relay. I think a big clue is this is the same wire that provides power through the flasher fuse to reverse and turn signals. Though I blow no fuses! So I'm not sure. If I'm not blowing the flasher fuse or the fusible link for that circuit, should I be looking ahead of the fusible blink at the white wire that powers the fusible link?

If I pull the flasher fuse the car doesn't die either, though it not blowing that 10A fuse is confusing.

Edited August 6, 2019 by Usain_Boat
Added information on the flasher fuse

[Zed Head]

23 minutes ago, Usain_Boat said:

Well I've already traced power for those circuits. I lose power at the fuel pump relay output (the relay clicks off) and I also know I lose power on the wire that provides power to the solenoids in the fuel pump control relay and fuel pump relay.

Do you lose power to the ignition system also?  The coil.  You're focused on the tail of the problem instead of the head.  Go all the way back to the battery.  You might even have a bad battery connection.  You haven't really said that everything else maintains power, only that certain relays lose power.  

And don't assume that voltage equals current.  Seeing voltage on a circuit just means that it has the potential to do something.  Without a ground nothing will happen.

Be the electrons...

 

[Usain_Boat]

Tested with it dead, the coil has 12.8 volts as to be expected with the engine not running. Testing from anywhere on the circuit that provides power to the flasher fuse, even at the fusible link that protects the fuel pump power as well as to the ignition relay to be switched into the White/black wire gives a reading of mV to ground and the battery. With it dead unplugging the reverse lights and plugging them back in turns the car back on and while doing this I noticed the right hand reverse light is much more dim than the left hand light.

[Zed Head]

4 minutes ago, Usain_Boat said:

With it dead unplugging the reverse lights and plugging them back in turns the car back on and while doing this I noticed the right hand reverse light is much more dim than the left hand light.

Are you unplugging each light individually, at the socket, or unplugging the reverse switch on the transmission?  You said "them" which implies both, but you have to unplug each individually if you're actually unplugging the lights at the socket.

[Usain_Boat]

1 minute ago, Zed Head said:

Are you unplugging each light individually, at the socket, or unplugging the reverse switch on the transmission?  You said "them" which implies both, but you have to unplug each individually if you're actually unplugging the lights at the socket.

Yes, sorry for not clarifying. Switching the trans out of reverse or unplugging each bulb individually will return power to the wire.

[Zed Head]

So you can unplug a single bulb, either side, and power comes back?

I don't have a solution in mind but do see that the ground wire for the bulbs is back at the ignition relay.  Same for the signal bulbs.  You might find that ground wire and either replace it with a better ground wire or clean up the connection.

My latest guess is that the ground circuit is opening due to heat from the extra current.  Similar to how the bad battery connection open up.  Find that ground wire and make sure it's right.  It could be the connection at the relay mount or the connector shown in the diagrams.

[Usain_Boat]

I had to unplug both bulbs for it to turn on again, though I didn't try just pulling the dim bulb.

[Usain_Boat]

That ground looks clean to me, no corrosion and good continuity to ground.

[Zed Head]

How many ohms?  What does "good" mean?  What does "ground" mean?  "That ground looks clean".

I can only offer clues.  You decide how to run with them.  Think in terms of circuits.  Current flow.  You're losing current flow somewhere.

[Usain_Boat]

Around .5 Ohms to ground where my leads have a resistance of .2-.3 Ohms. I understand that I'm losing current just baffled as to where. It stops dying in reverse with the flasher fuse pulled or the reverse switch pulled, yet I have physically traced the reverse circuit and nothing is grounded out. Also even with the reverse circuit disconnected the left tun signal still kills the car.