head lights intermittent failure

[robobobo]

Hi
I have been getting a total loss of headlights intermittently.

When this occurs the high beam telltale light always lights up in both side lights and main beam settings on the switch.
When the fault is occurring I can reset it by tapping the fuse box in the area around the 19 relay, sometimes this allows the lights to come on until the main beam selector is switched when it then goes off again.

After getting a bit more aggressive with the tap on the fuse box, the problem usually vanishes. Until the next time, happening more often though.

I have cleaned the earths prior to this problem and refitted them all both near fuse box and in engine bay. Also i removed and cleaned fuses.
I have not investigated the wiring or changed relays as the wiring is such a bundle I am afraid to disturb it too much. Does this sound like a problem anyone else has come across?

Every time it is cured at the same time as tapping the fuse box so im pretty sure it lies in a loose connection or dodgy componant, just need to know where to start to investigate and change things.

The only difference I have made is to fit a Buzzer relay to let me know if I leave the lights on with ignition off. When the problem is occurring and the high beam light is on, the buzzer only buzzes on side lights. When fixed it buzzes on both as normal. ( it worked fine with the buzzer relay for ages before this problem ) On my van the 19 relay was fitted as standard, it is a syncro caravell 2.1 dj with factory aircon, rev counter and central locking.

Any advice much appreciated, im on a 4 week tour of France from friday onwards.

thanks electro mechanical geniuses and below

Robin

[itchyfeet]

Try removing the mult plug behind the fusebox and checking for corrosion, earth crowns often corrode due to water leaking from the windscreen so stands to reason fusbox could also get damp

headlights connect via c and e connectors which are the central lower and middle connectors,

thinking about it if you loose both sides more likely a and b connectors which are either side of c and e

when they go can you flash the lights?

Cheers

Paul

[robobobo]

Funnily I can't get the problem to start again now. I'm 90% sure that the flasher did work when the lights failed.

I'll remove and clean the rear connectors to be sure and see how it goes!

Thanks for now !

I cleaned them all, looked pretty good though. Some were a bit tight so maybe there was some light corrosion. Hope that's sorted it!

[robobobo]

So the problem keeps coming back. I used switch cleaner on all the rear connections pulling them on and off twice, that cured it temporarily although it faltered a little changing from low to high beam at times. Now its back to stopping dead, not funny on any road at night.

I have now brought relays and wiring to upgrade the system and had planned on using the California Dreamin method. I would still like to get to the bottom of the problem and am concerned that I will have the same issue if I use the wiring behind the headlights to trigger the relay.

Where would be the best point to take the trigger wire for the High and Low beam? Bearing in mind it is always fixed by tapping the fuse box so the problem is in that region. Im happy to test specific wires but am a bit lost on which. Im thinking it best to bypass the problem area although it would be nice to get it to work as it should before proceeding with the upgrade.

The rear lights continue working when the fronts stop, the fronts do not work on side lights, dip, full beam or flash when the problem occurs. Could it be a sticky relay?

Now the nights are closing in

thanks

[marlinowner]

Its interesting that the tail lights still work when the side lights fail, on both sides. The side light and tail light for each side are connected together at the board behind the relays the only difference is that the front lights (including head lights) are connected though plug C and the tail lights through plug E. However the tail lights are earthed in the engine compartment, whilst the front lights (including headlights) are earthed near the relays. do the indicators work when the lights have failed? They share plug C and are also earthed near the relays,with the front lights. I don't think the fault can be at a switch or relay, otherwise the tail lights would fail at the same time, to me a problem at the earth crown seems most likely.

[robobobo]

Hi Marlin
Im not 100% sure about the indicators, annoyingly ill have to wait until the problem arises again. But the high beam indicator light comes on when the lights go off

I did clean the fusebox earths not so long ago but ill double check and try again, ill perhaps put some new earth crowns in to be sure. Are there any other earths to double check, the engine has a new one and the main battery earth is good. I guess that when I tap the fuse box (which can cure it) it moves the wires on the earth crown, can I trace the particular earth for the headlights easily at the crown or is it just part of the loom coming from the front.

If i am putting a new earth on when I add the relays behind the headlights then the original one will become redundant I presume

thanks

[marlinowner]

The main beam warning light coming on makes it really likely to be an earthing fault, the circuit is going to earth through the main beam bulb and the warning light, in the same way that you see rear lights behaving with a bad earth when the indicators or brake lights come on. Because the warning light resistance is more than the headlight bulbs, most of the 12v will be across the warning light so that will light up, the voltage across the headlights will be too low for them to produce any light. The left and right side headlamp have separate earth wires to the crown (unless the wiring has been modified), so as they fail simultaneously it seems more likely that the earth crown itself has a bad connection to the body. Fitting a new crown, maybe as part of the relay modification, would be the way to go.

[marlinowner]

Sorry missed the bit about the main beam tell tale in your first post!

[robobobo]

Sounds good to me, thank you for the advice. Very well explained
Ill take the crowns off completely and redo all the connections and put new earths for the headlights alongside the relays behind the lights.