lights not working?

[79rolla]

hey mu brothers got a nissan pulsar gti with big fog lamps at the front in the center
he just replaced the plug thing on the back of the light
because the conncections stuffed out or somthing and only one light was working but now he has replaced the plug neather light is working
he cant find any blowen fuses or other fults... dont know what he has cheaked but looking for ideas or is there another hidden fuse box or somthing?
sorry about being so vauge but i havint been working on it and dont know what hes done...
thanks heaps

[Ae92typeX]

I'd pull out a multimeter and start withe the plug. if one was working than didnt after he did the plug...
Also check the bulbs
check the relays
earths
+ feed

not much that can go wrong with lights really, just work methadologically through it.