lights and electrical gremlins

[ozy]

hey there, ive finally started looking at my Zed, and in particular, the annoying light situation.

 

originally, If i wanted dims, i got dims.

if i put on the full beam, id lose 1 dim and get 1 full beam.

 

so today i chased the wires and cleaned any connections

(except the actual headlight, fuseboard and lightswitch area, i know im very bold)

 

but i want to see if this diagram is correct for a generic light setupl.

 

 

 

i believe these are the same. as terminals 85 and 86 do not care about polarity (see pics)

 

my wiring is like this, but now

 

parker = front indicators "on" (like foglights)

dims = ok

full beams = nothing

 

 

ideas? or should i get off my arse and continue cleaning the points

or would you recomend new relay switches / wiring?

[Zedman240®]

Alot of the times when the headlights play up it is due to the fuses. Sometimes they are obviously burned, but sometimes they seem ok but are broken behind the end caps internaly and it can't be seen from the outside. Either a multimeter is needed to check for continuity or more spare fuses to replace a suspect one.

 

Bad earths are another PITA that are hard to locate. I'd check all the obvious before you spend a weekend ripping it all to pieces!

[ozy]

ive an earth problem too i think. it manifests when i hit a pothole by killing radio, revs, fuel guage.

 

cool, fuses fuses fuses!

 

if not, ive a multimeter laying about here somewhere.

 

p.s. is that diagram ok for the light wiring?

[Zedman240®]

Is your zed a 260? You may want to check (if it is a 260) the fusible links under the bonnet in front of the brake master cylinder. I had a corroded fusible link cutting out my headlights over big bumps..

[Zeddophile]

originally, If i wanted dims, i got dims.

if i put on the full beam, id lose 1 dim and get 1 full beam.

 

This may be incorrect, but is it possible that the Zed headlights are wired in such a way that when you go to high beam on the switch, it intentionally cuts the low beam to reduce current draw?  Because from my reading of this quote, you are saying that (previous to no high beam at all) when you went from low to high beam, one side headlight would go completely out, and the other side would go to high beam.  If this is the case, I'd start by looking at the headlight globes (assuming you don't have sealed beams!). 

 

Check for power at the plug on the back of the headlight.  When on low beam, should have power at one of the three terminals (since low beam works).  One should obviously be earth (usually a black wire), which means the remaining one should have power when headlights switched to high beam.  If it does, change the globes (or headlights if sealed beams!), otherwise its more than likely a fuse or the actual headlight switch.  I don't think it will be a bad earth in the case of the high beams, as I'm pretty sure it uses the same earth as the low beams.

[ozy]

@zedman:

mines a 78 japanese fairlady z that originally had a 2000cc but has had work done on her and she now has a L28. I read an earlier post on fusible links, so i checked them. they looked ok, and there was a little corrosion, but thats cleaned now and i think my dashboard is a little brighter now!

 

@zeddophile:

will check out power at every point and finish checking fuses beside steering and the light stalk switch too. ill report back later.

 

I just wanted to ensure that my wire diagram was right, but its hard to check properly because whoever did my wiring used the same colours everywhere. pain in the arse to follow

[ozy]

finally looked at the main bulbs...

 

looks like my troubling left light has been attacked before, solder!

 

right bulb rear

 

left bulb rear

 

will try to get a replacement tomorrow

[dazzed]

the  relay wiring system is bang on the money ozy, if you want you can plug the wires into the right hand headlight conector  near the radiator support panel, saves cutting into the wiring loom, if you have h4s great ,if you put a better alternator on even better and run a heavy wire from the alternator to the starter motor ,reduces voltage drop

[ozy]

@dazzed:

that wiring diagram is one i found on the net, its exactly as is already in the car. i think ill replace it, no colours match the nissan system and even wires of colour A leaving the relay switch, turn to colour B 2 feet later after and its untidy so its really pissing me off.

 

alternator to starter motor wire? now this is a guess, but is this to give the starter more juice as soon as you start turning the engine? thats very clever.

 

and yes, im a novice!

[ozy]

actually folks, is it that big a pain in the arse to replace all the wiring?

 

reason being, while everything works fine, i cant help but think that it could be better.

 

1) when indicating, my rear lights dim a touch (its so minor a normal person wouldnt notice)

2) my instruments are still dimmer than satisfactory

3) things arent uniform in wire colour (where new things were spliced) or even where earths are located (like my headlights, right earth was at the rear of the light, left earth was inside the engine bay)

4) my engine bay has wires stopping here and there and it all seems disorganised (this annoys me the most)

 

these annoy me.

 

ideas?

what have the rest of you done?

[Zedman240®]

When you switch your indicators on, the reason is there's more of a load on the system; approx extra 50 watts! Its almost like turning on another single headlight. The only thing you can do is upgrade your alternator to something a bit bigger like a 280ZX one. One thing I have done is add extra earths around the car; I have an extra large one from the block to the body. You have to see current flowing through a car like a highway; you can't have 3 lanes in one direction and a gravel bumpy back road as a return. They both have to be as good as each other.

Your instrument globes may be the original ones from Nissan; might be going black on the inside so that's why they may be down in output. May have to stick your head under the dash and remove a globe and have a look. Some maybe burnt out. Speedo and tacho have two globes each...one may be blown.

Bothers me when people start hacking into the wiring. I like to leave it as it came from the factory. What I do is trace back their mods and undo it. Depends how far they have rooted it though...

[cathartik]

actually folks, is it that big a pain in the arse to replace all the wiring?

 

reason being, while everything works fine, i cant help but think that it could be better.

 

Give me a few weeks after the car gets back from the engineering etc and I'll let you know how I'm going with that obviously I'm doing an engine conversion but I've also figured that every single piece of 70's wiring that can be replaced with something more modern is being done. I'm expecting that I'm going to find it no real issue until I start spawning gremlins of my own. (Which is probably the point at which myself and friend will lay off the heavies and try again the next weekend)

 

 

[Zeddophile]

actually folks, is it that big a pain in the arse to replace all the wiring?

 

reason being, while everything works fine, i cant help but think that it could be better.

 

1) when indicating, my rear lights dim a touch (its so minor a normal person wouldnt notice)

2) my instruments are still dimmer than satisfactory

3) things arent uniform in wire colour (where new things were spliced) or even where earths are located (like my headlights, right earth was at the rear of the light, left earth was inside the engine bay)

4) my engine bay has wires stopping here and there and it all seems disorganised (this annoys me the most)

 

these annoy me.

 

ideas?

what have the rest of you done?

 

It won't be much of a pain in the arse.... However it will be expensive, as I wouldn't tackle a complete rewire if you are not fully confident with your electrical ability (and no offense intended, but I get the impression you're not?), which means palming the job off to an auto elec.  Manufacturers wire things up in seriously weird ways, and often seem to use twice as many wires as needed for the job, especially on switches for things like headlights and indicators.

 

3 + 4 you can do something about though - if you have wires that don't go to anything, you can remove the tape on the loom, remove as much of the offending wire from the loom as you can get to, cut it off at that point, then retape the loom up.  Where the wires change colour, you could always remove the different coloured section, and solder on a bit that is the right colour (assuming you can get some).

 

With number 1 - try running a new thick earth from the rear light assembly to a good clean earth point, this may help - also clean the contacts where the globe sits.  Also, are you checking this one with the car running, or just the ignition on?  If you are checking it without the car running and the alternator charging, try starting the car and then have a look, you may find the extra power provided by the alternator solves the issue.

[xa1973]

This may be incorrect, but is it possible that the Zed headlights are wired in such a way that when you go to high beam on the switch, it intentionally cuts the low beam to reduce current draw?  Because from my reading of this quote, you are saying that (previous to no high beam at all) when you went from low to high beam, one side headlight would go completely out, and the other side would go to high beam.  If this is the case, I'd start by looking at the headlight globes (assuming you don't have sealed beams!). 

 

Check for power at the plug on the back of the headlight.  When on low beam, should have power at one of the three terminals (since low beam works).  One should obviously be earth (usually a black wire), which means the remaining one should have power when headlights switched to high beam.  If it does, change the globes (or headlights if sealed beams!), otherwise its more than likely a fuse or the actual headlight switch.  I don't think it will be a bad earth in the case of the high beams, as I'm pretty sure it uses the same earth as the low beams.

 

 

 

This was also an issue I had in the 280zx, the original lights were as weak as p-ss, so I tried a heavier capacity globe, this caused the cut out effect as mentioned, the electrical system has an inbuilt load limiter

 

To remedy, I refurbed my spade fusebox and installed an Xenon set up with individual ballast units for each headlight, issue solved I now have lights as bright as a plane with less current draw than the original set up

 

As also mentioned good earth sectioning is essential in older cars, the more the merrier, I run my main earth to an engine mount and of course a newer heavier output alternator is of value

 

[ozy]

@zedophile: thanks man, oh yeah, no offence, im quite happy to advertise my novice stature, so when i say something stupid, itll be understood, and pity will be laid unto me!

 

was asking my uncle about the re-wiring, ...money!, so nevermind.

 

i think ill replace any wrong coloured sections alright.

 

i checked the voltage to the rear of the offending bulb and its wired correctly and drawing

11.5 volts to high only when beams on

and 11.5volts to low only when on dim.

which all sounds right. i cleaned the contacts at this last place and still, beam is weak.

 

to re-cap

 

dim: L & R = ok

full beam: L dims further, R = ok

 

now ill try moving the earth and upping it in the morning on the L side.

 

pain in the arse, chat to ye tomorrow

[dazzed]

ozy dont replace the wiring , it will never end other wise, the genuine wiring is fine , simple and reliable, the relay wiring diagram is right, and thats all you need, if the loom has been attacked before just put it all back to standard and wire in the relays neatly, no the alternator to starter dodnt give the starter more power, it is at the starter where the fusible link or the main supply wire is connected, so by running a wire from alt to starter,the voltage dosnt have to pass half way round the car to get to the main pick up, also keeps battery supply up

[ozy]

fuck it, gonna take her to a local guy, he knows shit inside out and will sort it out.

 

thanks for all the help!