Lucas push button starter solenoid SRB316 Switches and solenoids Classic Car Accessories Lucas Type 2ST 12 Volt Starter Motor Solenoid Relay, BCA4501, SRB316 Classic Mini Starter Solenoid with Push Button Lucas SRB316 BCA4501. TUDOR STARTER SOLENOID PUSH BUTTON TYPE BCA4501 3 TERMINAL BUT CAN ALSO BE USED AS 4 TERMINAL BY ADDING ANOTHER TERMINAL TO LARGE OUTPUT (NOT INCLUDED) AS FITTED TO MG, FORD, MINI, TRIUMPH, MORRIS ETC