Headlight - Switch problem

[Burnsy]

Driving home last night and I rotated my headlight switch a bit to get the dash lights to come on - they are temperamental and work as on off and don't dim anymore.  Anyway they went off and would not come back on and I then found that my headlights had also cut out.  They are now flickering intermittently and will not stay on.  If I hold the switch shaft I can feel a ping or spring type feeling when the lights flicker.  I am guessing that this is a switch problem but I just wanted to check peoples experiences before I go pulling it apart and following the instructions posted elsewhere here about fixing light switches.  Anyone else had this happen or got any suggestions as to what else to check first?

[Rabbitoh]

Can't shed much light (sorry) on your dilema, but I am also at the stage where my dimmer doesn't dim. There is a sweet spot where the inst. lights work and if you turn the knob, they go out.

[Glenn 'Stinky' Stankevicius]

When I had my dash and light switch out I found the spring that controls the dim (correct me if am wrong) needed cleaning up. I guess as the contact rotates on the spring it feeds more or less electricity through to dim or brighten the dash lights. Mine are better for the clean, but still temperamental.
Sounds like you are up for a cleanup and check of the headlight contacts at least, if not a replacement switch.

[smithy]

hi all i was in the same position as stinky, my switch showed a fair bit of corrosion on the dimmer spring, seems like this is a pretty easy part to fail given the amount of use. a bit of a clean up and it works though there is spot where it just refuses to work.
yours could be as simple as a build up of dust and crap....or not

i found the switch itself quite simple to fix. to remove the switch assembly there is a small button on the side of the switch housing that needs to be depressed while gently pulling out  the shaft.

dean

[Martin]

Burnsy,

I've just come home from a trip and saw this post; I'm surprised nobody has pointed this out to you:

The Workshop manual (section 12E - Lighting system) states
"A thermo circuit breaker is incorporated in the lighting switch assembly to protect the wiring from damage due to short circuits in any lighting circuit controlled by the switch.

"The thermo circuit breaker consists of a bi-metal blade and a set of contact points set in series with the lighting circuits. An abnormal flow of current through the circuit breaker, such as would be caused by a short circuit in a lighting circuit, heats the bi-metal blade sufficiently to separate the points and cause them to vibrate.

"The vibrating blade alternately opens and closes the circuit, thus reducing the flow of current and protecting the wiring against overheating and burning. The flickering light produced by the vibrating circuit breaker serves as a warning to the operator of the vehicle that a short circuit exists; however, it would still be possible to drive the vehicle at moderate speed until a service garage was reached."

Back in July 2004 I wrote a bit about repairs to light switches.  You'll find it here:  

http://www.fefcholden.org.au/cgi-bin/yabb/YaBB.cgi?board=howto;action=display;num=1091145598

It's on the General technical board, page 22, subject: Headlight Switch Problems.

Martin

[mcl1959]

My guess is that when you rotated the sitch knob, the coil on the dimmer sprung out and is now touching another part of the light switch which is causing the short circuit.
It may be just a simple case of pulling the dash out and removing the offending piece of wire.
Hope this works

Ken

[Burnsy]

Thanks guys, I can't shed any light on it   either yet as I have not got off my ass and checked anything out.  Sounds like Martin and Ken have hit the nail on the head though.  For the moment I am just using it as an excuse to leave school at 3.00pm when the kids do

[oldgmh]

Its also worth checking the foot operated hi/low switch as this can also cause problems with power to the headlights.