240Z Headlight problems

[silverz]

I know that 240Z headlights are not that great but a new problem has recently developed with mine that I am hoping that someone else may heve come across and know the cure for.

Lately my left hand headlight has gone very dim and yellow, it does brighten somewhat when the revs pick up but it goes even dimmer to virtually non existent when you put the lights on high beam.

I have pulled the light out and checked it out and it seems fine, I put a test light on the wires and it lights up but is dim as well. It is like there is less current getting to this light. The right headlight is fine. I have read somewhere it could be some sort of earth issue? if so where are the lights earthed?

I do intend getting the lights upgraded but don't have the time now and I also need to find a decent Auto Electrician, the last one I took the Z to here gave me no confidence.

I would like it to work well enough in the mean time to drive to work in the early hours when it is still dark.

it would be much appreciated If anyone could provide some advice.

Thanks

Peter

[ZED660]

You may find the attached link of some assistance.  Also check that the actual plug that connects from the headlight to the main wiring harness behind the grill is a correct fit, I have sometimes found that if I wiggle them around the headlight will dim if not correctly pushed together.

 

http://www.atlanticz.ca/zclub/techtips/electrical.htm

[aegean]

Sounds like an earth problem to me. Try taking the fuses out of the fuse box and cleaning them up with emery cloth and replace the fuses at the same time. Also follow the circuit back from the headlight and see if there are any junctions that attach to terminals. If so, take those apart and clean them up.

[ZD44TT]

hahah interesting i've had this too but in reverse.

 

if revs are below 4,500rpm then lights are fine. but once the revs pass that mark then my main driving lights go all dim. It's like a notch above parket but still very dim. even high beam is dim. It use to correct it self after i'd stop driving it over night........but now it's always there.

 

very odd........alternator seems to be in ok nick and charging correct volts.

 

i've looked at my fuse box and all seems fine.....i'll clean them up so you suggest.........

 

I hate wiring problems....argh.

 

[silverz]

Thanks all for the advice.  I tried the connector plugs onto the wiring harness - no joy there and I will try the other tips when I have time. In the meantime if I go to work that early I will ride my Pushbike! now theres an incentive to sleep in a little longer!

I did however manage to get a troublesome parking light to work so a had one small victory!

I wonder now if the wires at the switch were disturbed by the Auto Electrician when he tried to fix my indicators?

Anyway when I have time I will look into it all.

[Zedman240®]

My previous 260Z did that and I found a burnt fuse that didn't look like it was burnt. It was broken inside the metal end. Also, check for a good connection on the fuse clips. Pull out the headlight fuses and slightly squeeze the clips together so it grips the fuse a bit tighter. Hope it helps!

[JP240z]

Well I don't know if this helps..

But maybe if you look at your Current Guage or ammeter on the dash?

Mine drops below zero if I have my headlights on, blinkers on, and system going fairly loud... this is the only time my headlights dim.

[silverz]

Thanks for all the ideas, I don't know much about it but what really throws me is that it is only one headlight that is dim, the right side is fine, would fuses etc cause that?

[oldmates260z]

Datsun's have always suffered with earth switching and are typically the root of all problems.

However if the problem gets worse with revs it may be that the vibration when you rev the motor may make the connection worse or a wire maybe breaking down inside the insulation

If it is only one head light, it should be only the wiring to that side that is the issue. You will need to trace the wires to and from that head light.

Maybe time to rewire and use a relay so thet you do not have teh earth switching problem. I have some wiring diagrams to do the mod somewhere if that helps.

[aegean]

I don't have access to a copy of the wiring diagram, but a lot of manufacturers wire them up so that both sides are on different fuses - reasoning being that is one fails, you still have the other one. You should have a legend in the fuse box to tell you which fuse it is, or the owners manual. However, it may be one or more faults, with the likely cause being a faulty earth. It does no harm whatsover to clean ALL the fuses. When was the last time you did that ? Never ? Most likely. I had a 1950's car that had spent all day in an auto electricians shop to fix just this problem. I had just bought the car and it was being sorted for the roadworthy, and the lights were all over the place - high beam/low beam - all different lights on and in the end they couldn't sort it. I spent an hour or so cleaning all the fuses and earth wires at the lights, and they have been perfect ever since.

 

Yes, this would cause one headlight to be dim.

[silverz]

Thanks Aegean,

That puts it in perspective, I had better clean my fuses, yes you are right I have never done that. I didn't know there were that many things it could be. Do you know where the lights are earthed? is it at the switch?

[silverz]

Thanks to all for your advice. I now have two bright headlights, at the risk of looking like a dill I will admit I never realised there were two fuses, I just assumed there was only one. After the advice I went and check and lo and behold the 10A fuse for the left headlight was missing altogether - must have never been there since I owned the car. I put a fuse in and now two bright headlights. Got through rego like that and all....!

 

it makes perfect sense now one fuse goes and the must share the load somehow with the side with the blown fuse being dimmest.

 

Thanks again - maybe this should be in "the complete idiots guide"

[aegean]

I wouldn't beat yourself up about it - we all make stupid mistakes sometimes ! Sometimes the obvious is only obvious to others.

[silverz]

Thanks,

Certainly not beating myself up about it I am wrapt, I now have lights! I thought I was up for heaps at the Auto Electrician just so I could drive my car to work now I can spend on higher priorities.

Thanks for your help