XF high and low beam headlights don't work

The headlights on my 86 XF suddenly don't work. I suspect my 4yr old has pulled a wire, as I found a short ( 2" long) blue wire on the floor, one end male one end female) but don't know where it has been pulled from. I had a look at the relays under the left hand side of the dash and they don't look like the';ve been disturbed, but under the dash on the right hand sidfe there are a couple of white terminal cases from which this wire could have come. There is no fuse ( none marked anyway) on the fuse panel for the headlights, so that leaves the wire.

Further, I have no gas; the wires out the back of the switch have definately not been pulled, yet when I switch over to gas I get no gas through. I loosened of the gas intake into the motor and there is no gas coming through, yet there is definately gas in the tank.

So I'm thinking this blue wire could be some sort of safety relay; surely not responsible for gas and headlights though, although it sems strange that both the lights and gas went at the same time.