Connecting the car battery (11V--15V) to the relay coil. Tester will. consistency of the relay during each test session, Tester will light the. Check the relay before plugging into the tester. If it's a 4 pin.
12V Automotive Relay Tester 4 Pin 5 Pin Relay Test Tool Car Relay Diagnostic
12V Automotive Relay Tester – Universal Electronic Relay Diagnostic Tool
