A while back I fitted a fuel cutoff solenoid valve between the tank and the fuel filter. Both of these mounted forward of the tinware along the chassis. Thinking I would like to stop petrol going into a melting filter if there were a fire. I added a fuse in the feed to the solenoid as it should have had one anyway and then the next day when off for a drive to work to test carburettor tuning on a real road. A small bit of dirt jammed the solenoid plunger down holding the valve shut so I managed 10 metres of driving before it stopped permanently with LEAN on the AFR gauge, having emptied the float chamber. I suppose the added resistance of a fuse reduced the voltage on the solenoid just enough to make the dirt finally jam it. Parked the bus up using the starter motor and somebody reversed along the side of it during the day but didnt crease the metal so it will polish out. They did own up so I forgave them. I took the solenoid out, unscrewed the tube containing the plunger and tapped it on a table until it came loose. Cleaned it , reassembled it and it works again. But not before forgetting which way the fuel went while lying on my back and clamping off the wrong pipe before removing the valve. : .
I have one of these anti theft fuel cut off valves fitted on the chassis rail like you http://www.vehicle-wiring-products.eu/VWP-onlinestore/hoses/fuelpumps.php and the other day it started blowing the fuse so I have bypassed it for the moment until I can get under there and take it out.
Mine is a bit different - the coil has flying wires so there is no connector onto the coil itself. I would suspect a short the in the wiring to the socket that connects to the coil rather than the coil on yours - rubbed through insulation going through tinware without a grommet for example .. or frayed wire ends inside the plug going onto the solenoid coil.
