rear lights gone mad

[Wannabay]

This is what my rear lights do
side lights/main beam on - offside rear light OK; n/s rear light on but dim
ditto - press brake pedal - o/s brake light Ok; n/s light goes out completely
but both n/s and o/s brake lights work fine if side/main beam off
I have cleaned contacts and tried a new bulb in n/s rear but get same result
any ideas?
:?

 

[Clarkson46]

Check the earth connection of the lamp assembly to the body, both sides. Which type do you have as you don't give a year?

 

[Wannabay]

Check the earth connection of the lamp assembly to the body, both sides. Which type do you have as you don't give a year?

thanks, I'll check at w/e

and it's a 1971, small rear lights

 

[Clarkson46]

Common problem with that type of lamp assy. Originally they relied on a little spike puncturing the paint film to make the earth. In later versions VW fitted an earth tag on the back of the lamp house with gave a more reliable earth.