how to install smc pressure switch

[UnderdogGN]

hi, i have an 85 gn with the smc progressive alky kit on it. The "spray on" light would stay on so steve sent me a pressure switch to put in place of the guage. I know i need to take the guage off and put the switch in that spot, but it came with two small black wires and no directions. If someone could tell me where the wires go to that would be appreciated.
thanks