Well, lets start with the basics. When you enter the loader and sit in the seat, key off, does the instrument panel light up? You stated when the seat belt is fastened the light goes out, correct? If everything is ok to this point, then you should have power to pins 3, battery, 12, seat switch, 13 seat belt.....Turn the key on and now you should have power to pins 23 and 24 also. You can check the voltages with the instrument panel disconnected. If you can find a terminal pin that fits the sockets of the connector it will make the job easier. If you have power at these terminals then the system has the power to activate the solenoids.......When you checked for continuity did you use an ohm meter? The ohms must be .2 or less. A higher reading indicates an open in the circuit. Did you check the continuity of the ground wire at the solenoids connectors? I am also assuming the parking brake disengages when you push the enable button and that the engine starts.