Low beam fault

[Hawklord]

Went out yesterday evening and lights working fine but when started the engine to come home I had no low beam headlights only high beam. Luckily the drive home was on country roads and only annoyed a few drivers with the high beam. Tested the headlights this morning and they are working correctly and can't get the low beam to fail. Any suggestions would be appreciated as I am now apprehensive about going out in the dark.

 

 

[steve b]

Are the fuses and board connections all ok? The quality of blade fuses is variable to say the least.

Steve

[Hawklord]

I haven't checked the fuses yet but looking at wiring diagrams it seems that there are separate fuses for right and left low beams so it would be very unlikely for both to fail intermittently at the same time.  I am now suspecting that it could be the indicator stalk switch as recently it has sometimes been difficult to keep the indicators on as the switch flicks back to the central position without turning the steering wheel back and the mechanism seems quite loose. 

[pete3000]

I'd go with the stalk switch. the resting position is for dipped beam, if the flash and high beam work?

[Peaklander]

It could also be the headlamp relay not contacting properly. I've had this recently. Lost dipped lamps suddenly at 50mph in the very very dark and had to flick beam on quickly. It's a bit disconcerting. They came back several miles later and then failed next morning at 6am before I'd had time to look. I cleaned the relay contacts and all has been good.

Here's a diagram that I posted recently on another thread.

 

[paime]

The headlight stalks are always failing so best to start there. You can take them apart and check the contacts are clean and the springs are all intact. They're annoyingly expensive to replace unfortunately!

[Hawklord]

Thanks for your replies and I today fitted a new Lucas headlight stalk and cleaned the relay contacts (which looked clean anyway). Fingers crossed that this will fix the intermittent problem but then again it is a Land Rover.

 

[Hawklord]

Frustratingly my headlight issue has returned, went to come home last evening and no low beam so had to drive with high beam. 

When back home I toggled the light switch and indicator stalk multiple times and eventually the low beam worked again but I don't knew which of the 2 switch operations fixed it. When not working the low beam does not come on with the headlight switch in either the low dip or on position but in the on position the high beam and high beam flash both work via the indicator stalk.  When working the low beam comes on full brightness with the light switch in both low dip or on position but this I think is due to the fact that I have a Boomslang wiring harness for the headlights. One other observation is that when moving the headlight switch from low dip to on I can here a clicking noise like a relay from behind the instrument gauge panel which I can't say I have noticed before, is there a relay there and if so what does it do and could it possibly be the cause of my problem.

 

 

[Peaklander]

Yes there is a relay. Look at the circuit I showed just a few posts up the thread.

[Hawklord]

Problem now fixed 👍

Tried the lights today and they didn't work. Then remembered that the Boomslang wiring harness has a relay for the low beam so wriggled the relay and saw a small spark from one of the connectors and the low beam came on. Pulled out the relay and the terminals were very rusty, so cleaned them up and now all good.