Lighting Issue

[jpw58165]

every light on my Z works except the tail lights, any ideas

 

headlights low and hi-beam

turn signals

hazards

brake lights

reverse lights

instruments

dome

dash

 

taillights will not come on at all

 

 

 

[SteveJ]

What year Z?

[71Nissan240Z]

Verified the bulbs are good? Checked harness for power? Verified ground? Checked for corrosion? Thats the low hanging fruit. Do the front parking lights work? If no your hazard switch should be taken out and apart. Check each contacf for continuity, clean if necessary with sand paper. Be gentle. This solved my parking light issue in the past.

[SteveJ]

Depending upon the year, it could also be fusible links. Until the OP gives the proper information, it's just all speculation.

[jpw58165]

it's a 1974 260Z, yes the front parking lights work, every light works except the rear tails

[SteveJ]

Please clarify what circuit is not working.

The following circuits go to the rear of the car:

1. Brake lights

2. Parking lights (aka running lights)

3. Turn signals

4. Reverse lights

 

Also, if you download a copy of the FSM, in the BE section, you will find breakouts of each circuit. That will help with troubleshooting.

[jpw58165]

parking light circuit/running lights for the rear taillights only, everything else works

[SteveJ]

Look at page BE-14.

Are the rear side markers lit? Remove the back panel. Are there signs of splices? Use a voltmeter and check for voltage to ground on the green/white wire.

[jpw58165]

OK, I do not have power on the green/white wires at the back panels.

 

I also noticed that my front left headlight was out, it came on when I hit the hi-beams and stays on if I go back to lo-beams. If I turn the lights all the way off the front left headlight will not come back on unless I hit the hi-beams.

 

One time when I was cycling the hi/lo-beams like his all my lights came on, even the rear park/driving lights and stayed on after I switched back to lo-beams. As soon as I turned the lights off and back on the rear lights never came back on and the front left headlight only comes on if you hit the hi-beams.

 

I do have power on both sides of the fuses for both headlight fuses and taillight fuses when I turn the lights on.

 

Any ideas? I assume the head and taillights tie in the wiring somewhere and all share a common ground.

[SteveJ]

OK, I do not have power on the green/white wires at the back panels.

You aren't measuring power unless you are using a wattmeter. I asked you to measure voltage. If you don't have voltage on the body harness side of the connector, you won't have lights.

 

I also noticed that my front left headlight was out, it came on when I hit the hi-beams and stays on if I go back to lo-beams. If I turn the lights all the way off the front left headlight will not come back on unless I hit the hi-beams.

That hints at dirty connections in your wiring if it is stock. Did someone convert the headlight circuits to use relays?

 

One time when I was cycling the hi/lo-beams like his all my lights came on, even the rear park/driving lights and stayed on after I switched back to lo-beams. As soon as I turned the lights off and back on the rear lights never came back on and the front left headlight only comes on if you hit the hi-beams.

 

I do have power on both sides of the fuses for both headlight fuses and taillight fuses when I turn the lights on.

 

Are there any signs of splices or other "modifications" in the wiring harness?

 

Any ideas? I assume the head and taillights tie in the wiring somewhere and all share a common ground.

You assume wrong. Look at the wiring diagram breakouts in the FSM. Also please answer the other questions I asked. They are intended to get pertinent information to solve your problem.

[jpw58165]

I measured voltage with a multimeter, set to VDC, and I have 0 VDC when measuring from the positive lead to either green/white wire and negative lead to common ground.

 

I have no idea if the headlight circuit was converted to relays, where would I look?

 

yes, there are splices in the wiring, the rear panel was converted to some aftermarket light set-up when I bought the car. I do not have power coming into the splices, so I don't think the splices are my problem right now. I do plan on cleaning up all the wiring though.

 

When I looked at the schematic diagram, it looks like the head and tail lights do share a circuit, as indicated by a GW wire going to both.

 

Please help, I hope I gave adequate info, thanks

[SteveJ]

I measured voltage with a multimeter, set to VDC, and I have 0 VDC when measuring from the positive lead to either green/white wire and negative lead to common ground.

And as I said before, without voltage on the green/white wire, you will not have lights. So what you need to do is figure out where the circuit has been interrupted.

 

I have no idea if the headlight circuit was converted to relays, where would I look?

Look in the engine bay and under the dash. You will see non-factory relays. Extra wires around the headlights are a clue.

 

yes, there are splices in the wiring, the rear panel was converted to some aftermarket light set-up when I bought the car. I do not have power coming into the splices, so I don't think the splices are my problem right now. I do plan on cleaning up all the wiring though.

At this point, I will assume the worst and say that someone hacked up the wiring harness. That is based on you saying that you experience intermittent functionality and that you have seen splices in the circuit. Until you confirm continutity between the green/white wire at the headlight switch and the end point in the body harness, you have not proven the splices do not relate to your problem.

 

When I looked at the schematic diagram, it looks like the head and tail lights do share a circuit, as indicated by a GW wire going to both.

 

Please help, I hope I gave adequate info, thanks

The headlights and taillights DO NOT share a circuit that is germane to this problem. The running lights on the front and rear DO share a circuit on the POSITIVE side, that being the green/white wire. It branches off in the dash harness. The front and rear running light circuits DO NOT share a ground. That is why there are two places marked "Earth Point" in the drawing I referred you to.

 

At this point, I suggest you join the Z Club of Texas or the Cowtown Z Club and find out who is good with wiring. It is difficult to diagnose a hacked up harness online if the owner does not have good knowledge of electrical systems.