I was at the scrap yard getting a new headlight unit for my escort van today (mine had water in it) and I took the 2 front spot lights/fog lights from this C plate escort with the intention of putting them onto my G plate mk4 escort van. To take them out they were earthed to a bolt on the lower right hand side of the engine bay, and then they had a plug fitting into a wire just by the fuse box.

I got them home (fitted the headlight first) then set about trying to get these spotlights in. The earth is in the same place, but obviously as my van is 4 years older so the engine is slightly differently laid out. So I haven't got a plug for the wiring which was sort of half expected, but I tried to the wire the lights straight from the bulb wiring on the right headlight. I wired it into the yellow wire and the white wire separately but nothing happened either time. So I tried a just putting the wiring straight from the battery to test if it was even working, and nothing happened, so I cut off one of the lamps, earthed it and held it to the battery but nothing happened atall.

I've taken them apart, the bulbs look basically brand new, filaments still intact, the wiring is all fine and the connections were all good, but I cannot figure out why it won't work, im just looking for any help, I'm sure it's something stupidly simple and easy that I'm overlooking, or i may need to get a whole relay and switch and fuse fitted in which case I probably won't bother so any ideas are gratefully received, thank you!