Surge Tank Wiring Diagram
12 volt positive from key or fuel pump on/off switch will land on terminal 86
12 volt positive with large enough wire to support fuel pump needs will land on 30.
87a will run to 12 volt positive on fuel pump itself. Ground of fuel pump can be run to battery or chassis if chassis is grounded.
Ground will need to be supplied from battery or chassis to level switch in tank. Other lead of level switch will land on terminal 85.