Page 1 of 1
Headlamp Switch Troubles
Posted: 23 Dec 2012, 09:29
by Matt and Danni
Hello,
I've never posted anything on here but have been using the site for information for a little while - it's ridiculously helpful!
Here goes:
I have a 1986 1.6D and the headlamp switch has just gone after a journey last night.
The switch was physically stuck on the main beam position, however only dipped lights were on.
I removed the switch to turn the lights off and on inspection, the X terminal (ignition feed?) has a nice blob of melted plastic on it and it sticking slightly out of place. On the black box that the switch pushes into, i noticed the corresponding wire was a bit frayed and a little burnt.
Is this a problem that goes further than the switch?
I'm guess it would be solvable with a new switch (251941531L) and some re-wiring, but would I be mad in thinking that I could just wire up a basic electrical switch for the main lights to have them on or off, just as a temporary solution to drive home for Christmas, until I can order a new switch?
Thanks
Matt
(sorry about my lack of electrical knowledge!)
Re: Headlamp Switch Troubles
Posted: 23 Dec 2012, 13:14
by colinthefox
Matt and Danni wrote:
I removed the switch to turn the lights off and on inspection, the X terminal (ignition feed?) has a nice blob of melted plastic on it and it sticking slightly out of place. On the black box that the switch pushes into, i noticed the corresponding wire was a bit frayed and a little burnt.
Is this a problem that goes further than the switch?
It could be that bad contact on the wire which is frayed and burnt could conduct heat inside the switch and melt the plastic, causing your problem (or vice versa). Either way it would be wise to sort that problem before fitting a new switch. In the short term, as long as you have dipped beam working, and you can turn it on and off, then any switch that did that would get you home. (Not sure if it's a legal requirement to have main beam. Don't think it is.)The switch would need to be rated at 10Amps.
Re: Headlamp Switch Troubles
Posted: 23 Dec 2012, 13:44
by 1664
Matt and Danni wrote:The switch was physically stuck on the main beam position, however only dipped lights were on.
This is a bit confusing; the 'main beam' switch is on the stalk on the steering column. Do you mean the switch was stuck on the 'dipped headlight' position but only the parking lights (aka side lights) were on?
Remember also, the headlight will be on 'dim' if they are switched on with the engine off, they only come on full with the engine going.
Matt and Danni wrote:I removed the switch to turn the lights off and on inspection, the X terminal (ignition feed?) has a nice blob of melted plastic on it and it sticking slightly out of place. On the black box that the switch pushes into, i noticed the corresponding wire was a bit frayed and a little burnt.
The frayed connection is most likely what caused the heat damage in the first place - bad connections = increased resistance which gives rise to heating. Seems the resultant heat has had the effect of welding the switch in the 'on' position and buggered up the inner workings of the switch.
Matt and Danni wrote:Is this a problem that goes further than the switch?
Doubt it given the signs you've indicated
Matt and Danni wrote:I'm guess it would be solvable with a new switch (251941531L) and some re-wiring, but would I be mad in thinking that I could just wire up a basic electrical switch for the main lights to have them on or off, just as a temporary solution to drive home for Christmas, until I can order a new switch?
A new switch and sorting that frayed connection would sort it I'd have thought but the basic switch option is a bit optimistic I think. Looking at the wiring diagram on page 12.33 of the Haynes manual the switch is a lot more complex inside than a simple toggle on/off arrangement. Can try it if you want though...
See what your headlights look like with the engine going, might be stuck on but that's good enough to get you home. Try to sort the frayed connection first though, you don't want any more surprises....
E D I T: Apologies
'colinthe fox', I didn't see your post before I posted this and after that much typing it's staying

Re: Headlamp Switch Troubles
Posted: 23 Dec 2012, 18:55
by Matt and Danni
Hello,
Thank you to both "1664" and "colinthefox" The problem has now been temporarily solved with the help of a friend.
Apologies for incorrect terms, I meant to say the switch was stuck physically stuck on dipped, (not main) and only the side lights were on.
The wires have been re-crimped and attached to a very similar switch. It has three positions for off, sides and dipped, with dash illumination coming on with positions 2 and 3, sides and dipped respectively.
I have ignored the rheostat for now until a new switch can be ordered.
You hit the nail on the head with what had happened, as I found out taking the old switch apart.
Thanks again for taking the time to reply, much appreciated!
Matt