Headlights failing to operate.

[Stivva]

Good Evening gentlemen.

Another week, another hiccup!

 

My headlights (low beam and high beam, both globes) have stopped working.

The dash lights are working, the tail lights are operating, just the main headlight globes have stopped working.

 

I have taken apart the switch and checked all solder and wires which were fine.

I have checked the fuses. But still no luck.

 

Is there any other parts of the headlight circuit that are notorious for failing?

[Zedman240®]

I'd be checking the fusible links very thoroughly again. How did you check them? Best tool to check with is a 12v test light; make sure you have power at both ends of the link and remove and replace them and check they are clean without any corrosion.

[Stivva]

I have also put a multimeter on either side of the fuses to see if there is any voltage coming through either side of the fuses.

 

Edit; I checked the fuses for the headlights, not the fusible link.

[Zedman240®]

Multimeters don't always show whats really happening; It may be just reading a very small current (or voltage) coming through but not enough to light the headlights if there is a high resistance connection at the fuse.  Remove them and squeeze the fuse clips a tad and re install the fuses. Start a process of elimination.

[Stivva]

What order does the circuit run in? Is it switch, fuses, relays, lights? Is there more?

[Stivva]

Sorry, I forgot one important piece of the puzzle. The high beam does not work when I press the little button on the indicator stalk

[WA240Z]

I would check the relays, wire connection at the relays and negative conection to the chassis at the relays. Your car may have had after market relays installed at some stage, normally in the engine compartment. Because you are missing both high and low beam, I would check here. You will most likely find a single 12v supply to both high and low beam relays.  The negative on one side of the coil in the relays are most likely parelled up as well so check connection at relays and to the chassis.

 

Hope these ideas help, good luck.

[Cozza]

Hi Stivva

 

Try giving your headlight switch a jiggle, sometimes mine plays up on me. If this doesn't help and you have original wiring (no headlight relays) then read on.

 

I'm pretty sure Z's use a negatively switched headlight circuit meaning that once you turn on you headlights switch, your headlights always have power. They are fed directly from the fuse box (1 fuse for each side). The headlight switch does 2 things, 1st feeds the headlight fuses with power and secondly controls the negative and the dip switch then controls whether you are on high or low beam, again through the -ve.

 

First disconnect the connector block at one of the headlights, you will find 3 wires/pins (1 for +ve and 2 for -ve). Now check using a test light or multimeter that you have +12v at 1 of the pins. If you don't have power then your problem lies at the fuse box or in the wiring between the fuse box and headlights. (me thinks not)

 

If you do have power here, then using your multimeter, check for continuity between the -ve side of the battery and the other two pins at the connector block. Remember that 1 of these 2 does low and the other 1 does high beam so only 1 of these 2 pins can have a negative at any time. You should be able to toggle between them by switching between low and high beam.

If you don't have a negative then your problem probably lies at either the headlight switch or dip switch.

 

Hope this makes sense, good luck

Mick