Very strange, any ideas?

[Andrew S]

Have taken the Stag away for the weekend and have developed an interesting electrical gremlin

I am aware that my speedo dial is not illuminating. When I put the sidelights or headlights on, the temp gauge goes from 1/4 to 3/4 reading and so does the fuel gauge, 1/4 to 3/4.

I know the voltage stabliser can do this, but how can there be a link to the lights?

Any comments greatly appreciated

Andrew

[V Mad]

There is a bad earth at the stabiliser which causes it to put out a high voltage when lamp current flowing changes the voltage of the earth point. Check the earth to the speedo.

[Andrew S]

Chris, thats great thanks. Also thinking about it, it could be the earth has come adrift maybe on the gauge which is why the light on the dial is not working. Will have a look tomorrow night

Cheers
Andrew

[GDPR]

Or the bulb may have blown too? Just a thought.....

Happy Easter!

[Andrew S]

Quite right Russ

[Andrew S]

Chris, you mention that it could be a bad earth at thestabilser end. From memory, there are just two green wires that go on the backof the unit, so where does the earth come from? I pulled the dash forward andreplaced the bulb which just turned out to be a dirty connection and also thebulb had seen better days. I then noticed that there was a large double wiredearth lead with a ring on the end loose on the speedo. Replaced bulb and allworking as should and then tightened the earth wire to the speedo gauge clampnut that holds it to the dash. Fired her up tonight and I am still having thisover reading problem only when headlights are on or sidelights.

[Andy Rundell]

I think the stabiliser earth comes from its body - when screwed to the back of the speedo it uses the instruments' earth..... If my memory is fading i'm sure someone will correct me.......

Cheers....... Andy

[Andrew S]

Cheers Andy, will have another look

[mikethemechanic]

If you still have problem it sound's like bad earth first point to check is battery earth to body and engine,if earth is poor then when using sidelamps rerturn current finds alternative way back to battery so causing what apears to be silly problems.easy check a jump lead from body to battery then engine to battery and if cures then sort the bad earth connection

[V Mad]

I think the stabiliser earth comes from its body - when screwed to the back of the speedo it uses the instruments' earth..... If my memory is fading i'm sure someone will correct me.......

Cheers....... Andy

Yes thats right. Earth is through the body of stabiliser, which is bolted to speedo, then speedo body is earthed via a connector tag to a black lead. The lead is probably loose or dropped off.

[Andrew S]

Cheers Chris, will have another look at the weekend

[Andrew S]

This is so typical but yet so simple. I took everyones advice and went for a problem with an earth. I had a wire that had a female end to it that clipped onto the back of the speedo. Clean it up and made sure it was a tight fit. There was also annother thinker wire combing two wires that had an earthing metal loop on the end. This was attached to the speedo dail securing bracket, the one with the finger wind up nuts on the back taht holds the dial to the wood trim. This I also cleaned and up and made sure it making good contact with the dial. It was only by luck that I noticed these two wires were in fact one and not even attached to the bodywork. So simple and so easy fixed. So, dont presume an earth is an earth until you do a continuity check with the bodywork

Thanks for the advice
Andrew