indicator adversely affected by another lamp

[Hippo75]

MOT failure "rear direction indicator adversely affected by operation of another lamp" ie the side lights wink when indicator is on. I've cleaned all the mountings and earths to the light clusters front and rear; slight improvement but still a bit of a wink so I'm not sure if it will pass. Any suggestions please? The alloy casings to rear lights are old and a bit cracked.

[karl]

broken wire maybe ? but i would put it down to bad earths ,clean them all

[Hippo75]

Thanks. Do you mean all the earths throughout the vehicle? I've cleaned others including the main strap, I've even rigged a new earth wire to the rear light casings, but it's still affecting the lights. Running out of patience and ideas....

[DougT]

It would seem as if the earthing problem is in the light bulb holder itself. So I would suggests you use a new indicator bulb or clean the contact areas thouroughly, clean where the pins of the bulb sit in the bulb holder and then check for any loose bits which connect the bulb holder to the earth.

You could try touching an earthed wire to the outside if the bulb holder with the indicator working to make sure that stops the side light lighting up.

Cheers

Doug

[Hippo75]

Thanks Doug. I've now done that, 2 new bulbs either side, no joy. Contacts all cleaned. I have a screwdriver light, connected that to side light terminal and good earth, still affected by the winker.

[jonochap]

Have you checked all the bulbs? Fogs...everything?

[limitedblack]

It will be a bad earth in the lamp unit probably corroded. The indicator bulb has power but can't earth all the current direct to the body, so it uses the other bulbs as they share the earth.

I don't know those units, but it will be the common connection from the lamp housing to the body of the van. It may be a corroded lead that looks ok.

If you can run the unit while hanging out the van then run a cable from a known good earth and touch it direct to the earth on the light cluster as near to the bulb as possible. If this cures the problem and the connections are all good then it is simply the earth wire.

If it doesn't cure it then check the front indicator, it may be the earth on that. If it is then the front side lamp should pulse slightly too.

[Retrohowla]

Had this issue myself recently, went straight to earths and cleaned them all, front and rear, no joy, replaced a couple earth wires, no joy, cleaned out the bulb holders, no joy, sprayed enough wd40 in all the bulb holders to flood the Serengeti and Bobs your uncle, sorted, next stop for me is new bulb holders, only a matter of time till it does it again.