Dipped/Main beam lights

[Nuffles]

Done a bit of an evening drive today and have ascertained that we have some lighting problems :/

Only one sidelight works. Yep. Easy, blown bulb or bad earth. Flick the switch to dipped beam and both headlights come on. No 'H/L' tell tale on the dash so I assume dipped beam. Hit the dip switch to give myself a bit more light and the lights turn off - back to only side lights, and still no tell tale. I had a look at the lights and can see only one bulb, is it a two-filament bulb? How do dipped/main beams work?

From what I can deduce the lights I DO have are either full beam with a broken tell tale and then no dipped beam, or I have dipped beam and the tell tale is linked in with the main beam and won't come on unless at least one bulb is working. I have a multi-meter so how do I go about telling what's what? From 30 meters away the light appears to be coming out straight ahead.

EDIT: Looks like they are twin filament bulbs, considering that neither side is working is it likely to be a dip switch problem (even though it still switches between one and the other, its just that other is off)? Or both bulbs gone in that filament? I'd only just grasped a basic understanding of Land Rover lighting but I'm going to have to start again now Is there any way to tell if the dip switch is in dipped position or main beam position so I can work out where I'm starting from?

[PSL184]

Try giving the dip switch a good squirt of switch cleaner or WD40 first. Sometimes they get gunged up. (get right up inside the switch). Also check the wires are still connected to the switch.

[mike.perry]

The bulbs on a Minor are twin filament, H4 if you have halogens.
Check the connections to the dip switch, Blue/White is main beam, and the bullet connectors in the wiring. If the dip beams are ok then it should not be an earth problem. If the main beam warning light still does not work when the main beam is on then it could be the bulb in the speedo is loose or blown or the unit has come out of the speedo.

[bmcecosse]

I suspect a wire off at the dip switch - because it's very rare for the main beam warning light to fail AND have both main beam filaments failing at the same time!

[Nuffles]

I suspect a wire off at the dip switch - because it's very rare for the main beam warning light to fail AND have both main beam filaments failing at the same time!

Had a look at the switch and had a poke with my multimeter and I'm getting 12v to the switch and the switch is giving good continuity across both sides so it's neither the feed nor the switch that is the problem, but I will have a better look at the connector. It came off the switch pretty easily but the contact could well be corroded. Both main beam bulbs are fine and not blown so it's between the switch and the bulbs.

[Nuffles]

The headlights still aren't working properly It's main beam that's not working definitely, which is blue-white wire. The switch works well, and I'm getting 12v live to the middle terminal. The headlights are both earthed well and both filaments in each bulb are good. It seems that the problem is between the dipswitch and the splitter behind the drivers side headlight. Problem is that the wire disappears into the loom and then into the dash behind the bulkhead. I dug my multimeter prong down into the splitter and there's no charge there so I don't think that's the problem but could cut it open if all else fails. Any other hotspots that are prone to failing or is it a single cable between the dipswitch and splitter? It doesn't seem to be fused or relayed and comes straight out of the bulkhead and into the loom.

Sorry for all the questions

[mike.perry]

If you remove the wires from the dip switch and connect the feed wire to the m/beam wire do you get any result? There is one bullet connector which splits left and right main beam lights and then another which splits the right main beam and the warning light.

[bmcecosse]

Wire leaves dip switch and splits to warning light - and to the headlamps. Since neither is working - the fault must be there! There is no easy answer - you need to look for it!!

[xpress]

what's the warning light?

[Nuffles]

The blue light in the speedo to tell you when you're on full beam.

Since this thread popped up again I'll say that I found the problem - the wire from the dip switch to the bullet connector that splits to warning light/headlights had come out of the bullet connector. Pushed it back in and it's been fine ever since.

[bmcecosse]

The headlamp main -beam warning light, if not working, should have been mentioned at the last MOT, although it's not a fail - it is an 'advisory'.

[jondoe997]

Nuffles just wanted to say thank you taking the time to post your findings on this problem. I had exactly the same problem last night and feared a lengthy investigation of electrics, not my favourite thing, but due to you it’s fixed inside 5 minutes. If I ever see you I owe you a pint.

[oliver90owner]

Unfortunately the message may well not get through.

Last active:Tue Nov 08, 2011 4:01 pm