You should hear it clicking when you put power on it, and take power off.

 

I bench tested it with a 12VDC wall wart w/ 1.0 amp output I heard it try but I didn't know if it was enough amperage. I put it back on the harness and tested it for change of flow by blowing through the pump port, and it didn't switch still. This truck is just for hauling scrap to the scrap yard so I'm not putting a whole lot of effort into retro fitting any of the only 5 options out there for a new valve on limited funds and I have only been using the front tank anyway because it has the sender that works so I flipped the valve around and swapped the ports for the rear and front tank, left the harness unplugged and am leaving the selector switch on the front so I have a fuel gauge.

 

You can just get a short piece of metal tubing and connect the hoses together, and leave the solenoid off. Since you know the switching solenoid does not work, I would be worried it was not letting enough fuel through the way you have it. If it works ok though, drive-on.