cant start lorry ?

Hiya my girlfriend has a E reg ford iveco cargo box which has been transferred into a horsebox many years ago. It has problems starting up. By problems i mean it doesnt at all. We were told by a heavy goods garage that the starter motor wasnt performing. I took this off and replaced it, connecting it all correctly i tried to start the lorry up and it didnt even try and turn over. All that happens is that its makes a "clunking" sound from what looks like a solanoid behind the battery. Could this be a solanoid or something else? If its not what is this? Thank you very much. Eden

Eden Frew
December 2012