disappearing headlights

[Joju]

hello all.
we recently had the headlights on the bus switching themselves off on the road. they could be coaxed back to life by poking the headlights switch more 'on'

however, this eventually had no effect, we drove for 20 minutes last week holding the switch 'on'

I opened the switch an cleaned up rather blackened contacts. We kept the lights on for an hour or two driving in the day yesterday, seemed ok.

then setting off home last night, it did its old trick for 10 minutes, then seemed to be ok for the rest of the run home, 45 minutes.

I was about to order a new switch but I thought I might put it to the collective wisdom first ... is it possible it is not the switch? I understand the switch switches a relay elsewhere, could it be that? I checked and wiggled the appropriate fuses. unfortunatly I have not the knowledge nor kit to do much electrical testing.

please pass on any thoughts.

[AdrianC]

they could be coaxed back to life by poking the headlights switch more 'on'
however, this eventually had no effect, we drove for 20 minutes last week holding the switch 'on'

^ this bit answers...

is it possible it is not the switch?

... ^ this question definitively. No, it's the switch.

I understand the switch switches a relay elsewhere

It might, it might not. I'd guess that it doesn't, since it sounds like your switch has burnt out. Adding relays would be a smart move.

I have not the knowledge nor kit to do much electrical testing.

They're really not as scary as they seem - there's plenty here who can hold your hand - and all the "kit" you need to do most testing is a cheap multimeter...
http://www.amazon.co.uk/dp/B0001K9XKW" onclick="window.open(this.href);return false;

[California Dreamin]

Joju.....depends on how sure you are that the switch jiggling was affecting the function.
It could have been pure coincidence and the rocking of the switch was just temporarily helping the true fault.
Switches definitely do fail but so do the earthing points (earth crowns above the fuse box)...these are certainly worth checking for corrosion.

Martin

[tonytech]

My van had case of intermittent headlights, turned out to be the ignition switch.
Clue was that the fan also switched off.
Temp fix was a piece of card stuffed behind the white plastic plug at the base of the ignition switch.


T
PS I still havent got around to the permanent fix.... but its only been 18months.

[Joju]

thanks for your replies. think I have to get a new switch, but this brings up the next question:
there are two switches listed on brickwerks, one for dim-dip models and one for non dim-dip.

I have no idea what this means or how I find out which we have!

http://www.brickwerks.co.uk/index.php/h ... m-dip.html" onclick="window.open(this.href);return false;

http://www.brickwerks.co.uk/index.php/h ... m-dip.html" onclick="window.open(this.href);return false;

[California Dreamin]

Dim Dip models are rare......from memory, the system was fitted on some late vans, ballast resistors behind the headlamp sort of give half powered lights, brighter than side lights but less than mains. I'm sure if yours had them you would have noticed this oddity?

Martin

[Joju]

just thought I should finish this thread ... put in a replacement switch from gunzl ... all sorted now.