I posted a while ago about my headlight problems and I've had a couple of auto electricians look at it without much success.

Can anyone recommend a 300ZX specialist who also knows about electrics?

Otherwise I'm left with a very expensive static display.

So there are sone oddball ideas had about lighting and how its switched on the 300zx.

Firstly both headlight dip beam and main beam are operated by relays rather than directly from the switch. The relays are located in the black box on the inner wing passenger side under the bonnet.

Next to the relays are individual fuses for the headlights. The relays have permanent power to them and the light switches in the car actual swith the negative (-) rather than power. This activates the relays and the lights then work. So its relatively easy to check the relays, pull them out of the base and check for power and the switching negative (- earth ) you can even temporarily fit a link to make the lights work. All of that applies to Import zeds and later UK zeds.

On early UK zeds they were equipped with dim dip system that made the headlights come on half power as a sort of day light running lamp, dim dip was quote popular at the time. So on the earlier zeds there is an additional dip dip module which is in line with the relays and this can be a source of headlamp problems. The module sits behind the passenger wing under the wing liner. Due to the position it suffers from bad corrosion of the connectors, they go really green and cause all sorts of issues.

If the problem is with the dim dip unit its just as easy to link it out.

Surprised an auto electrician could jot find the issue, that said they are a bit odd how they switch units.

So check the fuses, check the relays and and try a link in the relay base, if no luck its going to be the dim dip unit, which can be linked out anyhow.

Hi, I'd got some information on one of the Facebook pages about a multi-pin connector in the nearside footwell. This was also shown on a headlight wiring diagram I printed out but it didn't show the location.

So, on Sunday gone I had a dig around in there and low & behold the red connector wasn't seated all the way in, gave it an inspection then pushed it all the way in.

All lights are now working along with the horn and HICAS which also weren't functioning.

That's great news,

And I bet it's a great relieve knowing it's a simple plug rather than a broken cable somewhere you will never find.