glow plugs

[happypug]

Here I go again with eleci probs. Has anyone else had this fault, sometimes when starting up glow plug does not light up, then motor will not start this time of year. I have to switch on/off then plug light comes on, motor run`s fine otherwise. I know there is a relay behind the ecu, cannot find it to check, could it be that?
Anyone`s help greatly appreciated. Photo/position of relay would be good.
Not so happy pug.