Help!!! I have bought my fourth hazard unit due to a constant ticking noise (same as the 'tell-tale' noise that happens when you indicate) but every time I put the replacement one in there is a intermittent buzzing sound and sometimes a quieter ticking.

I thought this was because I had bought the replacements from Ebay and a local spares supplier but when I put the new one in from the main dealer today the same problem occurs.........anyone have any ideas?

Part numbers are: 4BO 941 509K B98 which replaces both

4BO 941 509C
4BO 941 509D

Many thanks.