Help rear fog light not working

[gti mad man]

T25 1.9 1987 waterboxer no front fogs
ok my rear lights work but not my fog light?>
have doen the following

1) swapped switch over
2) tried a new bulb
3) checked the fuse
4)no relay is present in relay slot 7?
5) removed the connector into the bulb holder and cleaned

Any ideaS?

[Mocki]

you do know it only works when the headlights are on , engine running dont you?

[gti mad man]

yup cheers

found the fault in the end , in the engien bay they had spliced into the original rear light loom for the towing electrics i.e sockets by tow bar this link must have been faulty as soon as i removed the socket from the circuit worked first time