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Discussion Starter · #1 ·
Hi folks,,
Just got my first 83 280zx 2+2 and going through the few problems it has.The left hand headlight comes on but is very dim and seems to take longer to come on then the right.Its not the bulb or fuse and still does it when i change the relays.The voltmeter in the car says 14 volts when I start it.Anyone had the same problem or think they know of a solution to find the fault??????

Danku
 

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my car used to do that. I could fix it by hitting the wires running to it under the guard. It was just a bad connection to the globe and was fixed properly when i put new globes in.
 

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First suggestion is to really thoroughly check the fuses.
Get some sand paper and clean the connections. Put new fuses in. Turn the lights on, and if no improvement, run your finger along the fuse so it turns around in the fuse socket. See if the headlight flickers... gets better/worse.

This is the most common cause of 1 dim headlight. My 81 was notorious for it.

How does it respond to hibeam?

cheers
Travis
 

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Is this weird, or what? It could be in your switch, the wiring at the globe, or your fuse. I guess if it's the fuse....then that means the electricity goes to one headlight first....then what's left over after that - goes to the other light....I am not sure how wiring works that way. If it is in your switch...then it means you have separate wires going to your switch for each headlight. You would have to find the connection at the switch that goes to the specific light you are having trouble with. I didn't know that the circuits were separated all the way to the switch. Or, you have a bad wire near the headlight globe. That would certainly explain why one is normal and the other is very dim! I had that same problem - it was a bad wire near the headlight globe. I determined which wire it was and ran another wire in it's place. It may be easier to just replace the globe and wiring. I would say that's your problem.
 

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OK, mini-lecture on electricity: My hope is that it will help a little when non- technicians are trying to analyze and trouble shoot simple electrical systems.

A very good analogy is to compare the electrical system to a water (or any hydraulic) system. Voltage is pressure, current (Amperes) is flow, wiring are the pipes, switches are valves and loads like lights and motors resist the flow and pressure develops across them.

When a load is wired in parallel like headlights, they all get full voltage and the amount of current available is divided between them just like splitting two hoses of off the main spigot. If one of them has some resistance like a crimp in the hose (rusty or otherwise bad connection) some of the pressure (voltage) is shared with the unwanted resistance, hence your pressure is lower at the end of one hose; in your case the light is dimmer. If a wire or connection is too small it is like trying to squeeze water through a small opening so again, lower pressure or voltage. That is why high current devices need large wires and solid clean connections.

Relays allow a small switch and wire to control a large current (a small electro-magnet attracts a steel plate with larger electrical contacts on them). If they have bad contacts or connections, you get current flow problems. If the relay is pulling in (and staying in) you need not check the switch and wiring that controls it.

A fuse is purposefully made to be the weakest link. They are designed to allow only a specified amount of current to go through them before they melt. If you are blowing fuses you have too much load for the design of the circuit (either a short circuit or someone added something). That is why you should not put a larger fuse in unless you fully understand how to size them. They are there to keep another (more expensive) part in the system from melting.

So, any connection can give an opportunity for oxidation to sneak in lowering your voltage at the load (headlight in this case). This includes ground wires which are often overlooked (this is the return path to the battery). In addition to checking fuse connectors, relays, sockets and the like, check that the frame and body panels have good ground connections as well.

Whenever possible use emery cloth (available at most automotive and hardware stores) instead of sandpaper, as it will leave a better finish and is not as likely to leave particles on contacts.

Good hunting,

RDB
 

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Discussion Starter · #7 ·
Thanks for the tips.I'll go and have another dig....If the problem is at the switch will it be in the actual arm on the colum itself or tucked away somewhere else???It is the same for high beem as well.....I'll post my results....

If it dosent require a hoist i can fix it!!

TA
 

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TA,

Your welcome, since the problem is on both the high beam circuit and the low beam circuit (there are two seperate elements in the dual-beam headlight) the ground path is the most likely suspect. I would try running a seperate ground from the negative battery cable over to the head light to see if this fixes it before I went digging into the column.

If you cannot see where the ground attaches to the body or frame, you can get a wire tap (crimps onto the main wire and allows a second to be crimped in at the same time) to the ground going to the lamp. You should see three (3) connections on a dual beam headlamp, two (2) are swithced hot ( + ) for high and low elements and one (1) for ground ( - ). This wire is usually black, but they are sometimes green or green with a yellow stripe. Be sure to use at least as big a wire as the original if you try it. The worst that should happen if you get the wrong wire is a blown headlamp fuse when you turn them on.

However, since you asked, I know that the early Z's have the switch mounted on the column and they are relatively easy to get at and replace by taking the plastic cover off. My GM van has the switch at the base of the column with a linkage from one end of the column to the other.

Regards.

RDB
 

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Discussion Starter · #9 ·
RDB,,

Checked all earths etc etc...Then had a look at the switch and bingo thats the problem....Had it working temporarily but it always goes back the way it was.Do you have to take the steering wheel off to get the switch out so I can put it on a bench???Ran out of time yesterday...Spoke to a guy from Zshop that said it was a commen problem and could fix for $45....I wonder how hard the problem is...Anyone anyone????

thanks
 

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Yep - need about a 22mm socket, and a steering wheel puller to get the steering wheel off, then you can slip the switch off the steering wheel column (there's just 1 lil screw holding it in place - pay attention to how the switch sits on the column - it can be tricky lining it up again later!)

As for "what is wrong/how to fix"... fairly safe to say, I think, that it would be the copper connectors. Once off, have a look at the switch. There is a small white plastic cover - pop it off. That reveals 3 or 4 1" or so long copper prongs... they raise and lower as you turn the light switch.

I'm guessing the little bumps at the end of each (which makes the electrical connection) are dirty. Carefully unscrew the prongs (remembering how they go back on) and clean them with sandpaper.

If that isn't the case... I'm not sure what would be the problem. It was the cause of my problems in my 79, and also why the park lights never worked on my 81.

Good luck.
 

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Switches/Relays

PA31,

You had mentioned that you had relays feeding your headlamps. If this is the case, the switches do not actually pass ANY current to the headlamps they merely pass enough current to turn on the relays. Again, if you have them and they are pulling in, the problem is NOT in your switches. Another point to consider is although I am not certain, I do not think there are seperate wires from the switches to the headlamps, as someone else mentioned there may be a connection point were one lead from the switches or relays splits to the headlamps.

Assuming that there are no relays the switches are highly suspect now that you have determined it is not a ground problem. It has been some 17 years since I had to replace these switches in a Z.

The actual head light switch is off of the stalk, the dimmer is off of the turn signal lever. Since both are part of the hi/lo beam circuits either or both could be suspect including their plugs.

I used my damper pulley removal tool in place of a steering wheel puller with success. (it also pulls small engine flywheels)

If you have a multi-meter you may be able to check the switch's internal resistance. It should be near zero when on. Sometimes a switch will show good with a low current (like from a meter) and still have high resistance to a load current.

Last, but not least, since the switches are capable of holding enough current to light the headlights there is more than enough to pull in relays. If you do not currently have relays for the headlights you could install them now off of the headlamp circuit that is still bright and avoid the cost of replacement switches and going into the column altogether. Any relays meant for fog lamps should do the trick. Be sure to fuse the common power feed for the relays if you choose this option. I would be tempted to add relays even if I replaced the switches.

RDB
 

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Discussion Starter · #12 ·
Thanks folks,
Bit of burnt stuff between the electrodes on the copper prongs...Works well though now and didn't have to remove the steering wheel either...Piece of advice to anyone with the same problem ....Dont remove the stalk lever from it's housing as its very time consuming to get it back in from wence it came...Thanks again to all for help, this site rocks....Tris
 
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