R129 headlight problem

[pollawyn]

The headlights on my 1992 500SL have suddenly started turning themselves on. Turn the switch on and off again switches them off but sometimes they come back on again. Is it simply a need for a new switch, apparently an easy and cheap repair, or is it something deeper?

[r129sl]

The circuit is relatively simple: switch, relay, lamp. I'd start with the switch. The relay is not expensive new (£100 ish) and there are millions on Ebay because it was used on the 124 and 126 as well.

[pollawyn]

many thanks, will do.