How the heck do you get at the fuel level sensor on a grey cab JCB 3CX backhoe? 'up the wires' mine is measuring open circuit, so it's either bust or the wire's fallen off. Parts book implies it's on the top of the tank (logical!!) on the left - ie close to the fuel filler cap but the tank being part of the structure pushes back into the cab and is covered in masses of plastic trim. I've got a new sensor but cannot get at the old one 