Headlights have dimmer switch!

Nov 09, 2003 8 Replies

She's just come back from an extended break at the health spa, and has a new trick! It's quite subtle really, for a Landy :0) The lights seem to dim and brighten slightly as we go along, almost like she's trying to entertain me a bit. Bloody annoying though, as it didn't happen before the refit. Seems, and this is only a vague idea, to happen off the throttle rather than on. There's a new alternator/coil/dizzie, so shouldn't be down to them, and the voltmeter is holding in the right area, so I haven't immediately suspected a bad earth, was wondering if anyone's seen this before ? Seems to be pointing at the voltage rectifier, but I'm not together certain :0( Opinions welcome.



Oh, it's a 1990 110 V8 csw in fairly standard trim.



`Agrippa


Lights will brighten slightly with any vehicle as the engine revs increase - the amount depends on how good the alternator is and how bad the battery is, so it could be your new alternator is better than the old (hope so, or why did you replace it!) or your battery is on the way out. On the other hand, the brightening and dimming could reflect a poor earth that affects the lights but not the charging circuit. This could be somewhere round the lights or the earth between the engine and the chassis, especially if the battery is earthed to the engine or gearbox. JD

I suggest you tighten the fan belt and if that does not get rid of the problem I will be surprised

Hugh

Nope, tight as you'd want. Bugger.Bugger. Reckon I'm going to be cleaning earth's this weekend :0/)

well did it work or was there another problem ???

Hugh

Belt was tight, 1/2 inch of play, I've checked the main earth's, all seemed ok, but I cleaned and refitted the spade on the engine earth, bloomin' lights are still flickering! I was going to check the connections in the light housing's last w/end, but it piddled down for most of it, and I don't have a garage.........so, more investigation this w/end, and possibly a trip to a 'man who know's, or I hope he does anyway :0)

Post the cause if and when you discover it please as I have a similar problem. I got rid of most of the problem by tightening the belt but not all of it. I'm thinking its a faulty regulator in the alternator.

Hugh

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