Glade you figured it out but l will tell you the reason that there is a box on this truck this older truck uses a Asian lpg system that is called a positive displacement lpg converter meaning that if 12volts is sent to the lpg fuel lock gas will be sent to the carb with no motor running if key was on so the way that the factory stopped this was to control the ground side of the fuel lock it would only allow gas to flow when the truck was cranking or running what you did was for test purposes only and should never be left to run like that. What could happen is with out the box it is very possible there could be a fire in the engine compartment.