Re: Interrupter pump - how do they work?
To me it sounds like you have connected the feed that goes to your Pump Switch to the permanently live side of the key switch
Move it to the other side of the key switch
In effect Battery - key switch - fuel pump switch
That way if either your switches is turned off the pump will not run
DAX GT40. Morgan 3.9 EFi, Worked by John Eales.
Renault Box, Always makes me smile!