Obsolete control box to repair/modify

Thanks for your reply, i am in Devon UK and the parts you mention would be fairly easy to source. I will look again at the wires and board and post some more info when available. I have put it all back together as it is needed for use and this fault wont stop it working we just wont know if there is a blockage on that side. This is something i need to resolve and easy simple parts to source and use will make all the difference. Many thanks.