I would use a 21w indicator bulb, yes it should light, see what voltage you have at sensor when cranking.

Some useful videos on youtube on just this way of testing, Google "Scanner Danner" american cars but principals are the same.

If codes are being set signal wires should be intact, you can check grounds with your bulb as well go from batt + to ground wire and bulb should light, good idea to have an inline 5amp fuse before the bulb though.