I’m booked in for an mot and whist doing my pre test inspection I noticed the near side main beam isn’t working. I’ve changed the lamp and checked the fuse but it’s still not working. I’m looking at the relays but the near side relay seems different to the offside so I’m reluctant to swamp them over to check it’s working. I’ve attached a picture of the fuse box for you guys to check everything looks as it should. Any ideas?

 

 

Cheers,

Chris.

Edited July 28, 20187 yr by Chris300

A further development is that when the dipped beam in on and I flash the full beam the dipped beam goes out.

A further development is that when the dipped beam in on and I flash the full beam the dipped beam goes out.

 

That’s normal. When you select your main beams, the relay switches over the power supply from the dipped.

Can you hear/feel the relay clicking when you switch between main and dipped?

I haven’t tried that yet. Thanks.

Your relay setup is the same as mine (UK spec) - ignore the extra blue relay by the fuses.

 

Check the earth harness connection to headlamp chassis (single wire) for the H3 bulb is in place.

 

I had this problem last week.

 

It was the connections on the bulb holder that were badly corroded not the bulb itself. Here's a link with a fix to the problem I had https://www.300zx.co.uk/forums/showthread.php?173675-Main-beam-bulb-tech-help&highlight=main+beam+bulb

Having read this. Can I just confirm how the headlights are supposed to work to see if mine are correct. On dipped just the round projector like one are on, on main beam they go off and the rectangular ones are on? I don't believe that both are ever on at the same time?

Having read this. Can I just confirm how the headlights are supposed to work to see if mine are correct. On dipped just the round projector like one are on, on main beam they go off and the rectangular ones are on? I don't believe that both are ever on at the same time?

 

Yep that's right. Dipped beam on and main beam off and vice versa

Its a pity they are not both on on main beam to give more light output.

Its a pity they are not both on on main beam to give more light output.

 

That’s an easy mod to carry out, simply take the earth wire from your dipped beams, put a ring terminal on it and earth it locally. This bypasses the earth seeking relay, the only down side is that when you flash your high beams, if your dipped beams aren’t on, they will flash too (which isn’t great for HIDs). There is a more in depth wiring method at the relay to avoid this scenario.

Edited July 30, 20187 yr by Joely P

Another headlight post reminded me to update this post.

 

After testing everything with a multimeter, changing relays and fuses the problem was still there. In the end it turned out the problem was between the lamp holder and the cable. (When I removed the lamp holder I didn’t realise you could spilt it from the cable, daft I know. This is why it took nearly 45 minutes to change the lamp first time. :bored: ) Anyway after separating the cable from the lamp hold I found that it hadn’t been fitted correctly and one of the pins had bent and not gone into the connector. Bent it straight, fitted it properly and then there was light. What a ridiculous problem.:death: