headlight wiring upgrade 260z

[Peter260]

Ok i have completed the a headlight wiring upgrade for my 260z;

2 relays [one low beam, one high beam];

8g wire from BAT on alternator via 30 amp fuse for power;

a pretty usual upgrade.

Now my headlights don't work at all; when i turn the lights onto low beam i cannot hear the low beam relay engage [click] but when i then go onto high beam i can hear the high beam relay engage [clikc]. Either way no headlights.

So basically i am a bit stumped. i have checked all my wiring and every thing seems in order; Any ideas or basic tips that i might be missing?

I will dig up the wiring diagram i used to help out also, but from memory it was a sound method which has been completed successfully by many.

I feel like i've been taking crazy pills trying to get this to work;

cheers;

Peter/

[MikeW]

When you say you checked all of the wiring what do you mean? Presumably you'd want to use a voltage meter at each step of the way. The fact that you can hear the relay click indicates that that the relay itself is properly wired to the combination switch (at least on the high beam) so the relay is being actuated. However, that doesn't mean that the relay has a power supply to pass through to the lights. Where is that main relay power coming from? Normally it would come straight from the battery or similar.

[Peter260]

ok. power wise i have tried two things with the same result;

1) BAT post off alternator to 30A fuse then to RED wire and RED with yellow stripe wires[spliced together].

2) positive terminal off battery to 30A fuse then to RED wire and RED with yellow stripe wires[spliced together].

The red and red/yellow wires are out of the main harness and have come from each of the headlights;

Before i say anymore i best get a wiring diagram for you all, i don't want people wasting to much time on me without it;

cheers;

both times the high beam relay is engaging when the switch is turned to high-beam.

[SteveJ]

Well, even though the wiring in my 73 has held up 9 years since I first did it, I don't recommend doing the cutting and splicing trick for the headlight relays. On the other hand, you're already cutting into your wires...

This is how I did it back then.

It hasn't given me any problems over the last 9 years.

Steve

[Peter260]

I don't see cutting into wires as a problem, once it is all wrapped up again with black electrical tape it all looks the same to me, as long as you solder/connect wires properly. The two relays mount under the relay box out of vision so it is really neat and tidy;

I will check my workings against your wiring diagram, it looks v similar but with 2 10A fuses instead of one 30A.

thanks again for your responses;

[Peter260]

ok the good news is that i was able to get the headlights working. both low and high beam work a treat.

the bad news is that now my parking lights don't work...

this needs to be fixed... anyone?

[DeMoore]

What was the problem with the headlights after all?

[Peter260]

in the other diagram i had the ground was on the 30 not the 87; I think when the other person drew the diagram he did it after he had done the job and simply mixed the two up;

anyone have an idea on parking lights?

I have the two part parkers; i.e. half the casing is flasher and the other half is parking light; not like the 240z where the parker uses up the full case [i.e. for 240z you put the flasher on and the globe simply gets brighter across whole case];

[SteveJ]

Peter, there have been many posts in the past about problems with parking lights/running lights. Please search for those terms to get some ideas of what to test.

The parking lights and the flashers are different circuits. You don't state the year of your 260Z, and I'm not sure if Nissan wired Austrailian market cars differently from US cars or if 260Zs later than 74 are wired like US 260Zs or 280Zs.

[Peter260]

it is 12/1975, i have done a search and it sounds like it might be a grounding issue;

I have also done a bit of work looking at my factory manual wiring diagram and there is a ground wire [up near the battery for LHD's] but near the booster for RHD's that 'i think' is currently not grounded. Someone else had this problem in an old post. fingers crossed that is what it is when i look tonight;

thanks again;

[SteveJ]

Grounding issues are common. So are worn/dirty contacts on the switch. Don't forget to check the integrity of your fuse. Pull it and check it with a meter. Fuses can look good and still be bad.

[TBone028]

So, prior to installing your headlight relays, were you parking lights working and now they arent? Or is this an existing problem that you are now trying to fix?

I dont know how the 260Z is wired, but, when I was hunting down my parking light issues (kept blowing fuses), I ended up disconnecting every single light, and slowly plugging everything back in one at a time. My problem stemmed from the parking light sockets in the front turn-signals. Years of wear and exposure to moisture were the culprit. They were corroded, and somehow causing a short to ground.

Went to the auto store, modified a pair of 3-wire turn signal light sockets meant for a ford van, and adapted them to work. Havent had a problem since. This was after rebuilding the combination switch twice, tracing every single wire, and testing every connection I could for 2 weeks.

My advice, if you have a battery tender, hook it up to your battery cables instead of using the battery itself while you are trying to trouble-shoot. Less voltage and you have a convenient power shut-off button. Also get plenty of spare fuses and beer. Electrical problems are the worst. I also went ahead and installed the parking light relay upgrade from MSA (built by Z'sondabrain). A very worthwhile upgrade and I wont have to worry about wearing out my combo switch anytime soon.

Edited April 22, 2010 by TBone028