71 Z Headlight Problem (left Light dim)

[24OZ]

Thats a great idea thanks, especially when considering what a pain they are to get too.

[EScanlon]

Did you intentionally re-wire your headlights together?

Normal wiring on the Z has them independent of one another. That's why everyone is referring to independent grounds and independent fuses.

But since you mention that they are wired together, I would say that you definitely have a connection problem at the headlight lamp itself.

I'm still in doubt over that "connection".

[24OZ]

Yes Enrique they're wired intentionally together. Not by me, so I don't know what the advantage of doing this was. Its a real hassle as it means that in the fuse box one of the left or right fuses is redundant (cant remember which one) this means I have to use a higher blowing fuse to cope with the extra current. I havent had any problems so far, just that the right is dimmer then the left, however i have seen it work so its a new problem and not because their wired together.

Thanks for the input any ideas as to why someone would bother wiring them up like this?? I guess this may have been done when the L28 and all the FI stuff was installed?? But then again why interfere with the lights for an engine swap? I dunno.....:stupid:

[EScanlon]

I would be MORE concerned about the wiring's ability to carry the current than about the fuse.

The Z has a notoriously ~weak~ electrical system, the wires are KNOWN to overheat due to minor resistances in parts of the system. After all that's why everybody has input into this problem you posted. But shunting BOTH headlights into ONE set of wires? I don't think that's a good idea.

Now if both headlights are shunted up by the switch, or fuse box, then probably you're ok.

I've heard too many stories about people melting their wiring harnesses due to overloads in the system to ignore this.

Just my 2¢

[24OZ]

Enrique, you are correct and I thank you for your 2 cents.

[wilby34]

an explanation for the dim light may be as follows.

If they are wired in series then that could be the problem. when you wire two resistors (in this case, light bulbs) in series, the second of the resistors always gets less electricity than the first, making it dimmer.

in case you dont know, a "series circut" is one in which the power goes to one light, and then from that light to the second one. from the second one, they are both grounded.

sorry if confusing at all.

good luck

[240zforfirstcar]

HI,

It sounds too me like someone before you had a problem with a bad connection in the fuse box and decided to move the wire from the bad fuse to the other head light fuse. Because now you are running 2 lights you had to use a bigger fuse. The problem with this is the wire is no longer protected for the right current. So when you next headlight blows and the filaments touch together your wire can smoke instead of blowing a fuse.

I sugest putting it back the way it was designed then locating the problem.

The light is dim because it does not have enough voltage to it. So find the missing voltage and you will find the bad connection.

Best way is to use a voltmeter ... Ground the black lead good...

Now touch the battery positive.... 12.6 or so... this tell you what 'full' voltage is ...

Now check each side of the fuse holder... try to get down to the metal under the fuse .... if yo get 12.3 or 11.8 you have lost some juice.... mostly likey corrorded contacts.... clean them and continue

keep working all the way to the light bulb..... If there is a firewall connector check both sides of it....

If you get all the way the the bulb and still have 12.6 volts then move the probe to the ground side ... this should be 0 volts....

if it is more then clean the ground connection bright and shinny...

If you don't have a meter you can use a test light and look for it to go dim... when it goes dim it means it has less volts just like your headlight.....

240zforfirstcar's DAD

[Datzun76]

Uhh did anyone mention to check the connection on the switch itself under the steering wheel? Thick red wire. I have been having a headlight problem as well. I keep having to turn the switch on and off to get just the headlights to come on and already replaced the switch. Good suggestions on the fuse box connections will give that a shot.

What would a Z be without electrical problems . Seems to be common among all Z's:ermm:

[24OZ]

Great advice, thanks guys....

I wish I had the know how to tacke such a job, as soon as I have some spare cash I'd like to take it to an electrical specialist to return it to its original condition. Saying that I may just hold out for my restoration in a couple of years time, with a Z specialist. As I said the car gets hardly driven never mind driven at night . 24OZ's are too scarce in the UK to be driven too frequently, mine only comes out in the Summer months and only at the weekends when the sun is shining, which is pretty rare in itself.

Have you guys heard of the British Summer?? Rain, Rain, Rain and maybe a heat wave for 1 week! :tapemouth Now you know why we have so few Z's left!

[Fun_in_my_z]

are the bulbs the same brand? i had (in moms van) one was a halogyn the other was some off brand. we changed the bulbs then didnt have any trouble.