headlight sparks

[guzzla]

After driving through the night a couple of week agao in my '96 80s with high beam and spotties on I pulled over for a rest and a walk around and decided to clean my headlights. The standard headlights were on but no high beams or spotties. when i started to rub the len on the passenger side i notied that when i bumped the chrome plastic frame and it touched the high beam lens it would spark and if held there would actually turn on both hi beams.

when the headlights are turned off (at the stalk) no spark can be made. a couple of mates had it pulled apart last night and were checking heaps of stuff with the multimeters but to no avail. We found the factory headlight blade fuses had melted but not blown and we seemed to be getting 12v through both terminals on the high beam light.

Im unsure how long its been like this and im sure im very lucky not to have had a fire so far.

your professional opinions is much appreciated.

[-Scott-]

It sounds like your high beams are negative switching (nothing unusual there) and the body of the light has become live (that is a little unusual.) Earthing the body of the light is providing a return path for current, so the lights come on.

You need to find how/where the light has become live - my guess is an uninsulated spade connector has been bent out of shape.

I think the melted fuse is a red herring - it's a nuisance, but not necessarily related to the random switching. At the risk of offending somebody, it could indicate your spotties are wired poorly - who did them?

[simkell]

It sounds like your high beams are negative switching (n

it could indicate your spotties are wired poorly - who did them?

yeah thats what i'm thinking, spotties are wired as positively switched not negative.

[guzzla]

It sounds like your high beams are negative switching (n

it could indicate your spotties are wired poorly - who did them?

yeah thats what i'm thinking, spotties are wired as positively switched not negative.

I did

We did look at that first and while not thoroughly, we did disconnect them when we started testing everything else so technically they should be eliminated as a problem. I am however currently searching here for the correct spotlight relay diagram usuing an illuminated switch so I can fully eliminate the spooties as the cause

I remember the boys saying that both terminals to the hi beam were showing 12v when it should only be one - the one comming straight off the back of the globe but this doesnt seem to be the case and it was getting late so had to bail

[ausoops]

both terminals will show 12v+ to frame when measured with a multimeter until you turn them on at the switch. because they are negatively switched the 12v is always at the light, the voltage will pass through the lamp and present itself as 12v on the other side. when you flick the switch the terminal will change from +12v to 0v.

[ricky1970]

Replace bulbs as one may be shorting to earth internally through the globe holder/reflector assembly, giving the globe a curcuit to work with. Also check and clean globe electrical connector plugs.

[guzzla]

Took it to my local auto sparky. I didnt really understand what id done but basically i wired into the earth side of the headlights only.

all sorted now and no more sparks.

thanks all for your help and as such i will no longer wire up spotties