Hi there, my first post to this forum so please bear with me!

My car (5 cyl 140bhp) has just begun to struggle starting. Basically, although the glow plug light comes on for a couple of seconds, there is no power getting to the glow plugs. If I carry on cranking the engine, it starts eventually with a cloud of smoke (presumably unburnt fuel). The haynes manual just says to check the glow plug relay - could anyone tell me exactly where this is or if there is anything else I should check.

Many thanks.