Ensuring your vehicle s automotive relays are functioning properly the Electronic Specialties 192 12- and 24-Volt Diagnostic Relay Buddy quickly tests and helps solve problems with your relay coils and switches. Designed to work with 12-volt and 24-volt relays and settable to 4-pin and 5-pin arrangements the tester works with the most common relays to ensure proper operation in your vehicle. The diagnostic tool examines the general health and functioning of relay switches contacts and coils applying a signal to the relay coil and testing the proper functioning of the contacts for a comprehensive test. If everything is correct the tool flashes a green LED light. If a problem emerges the red LED indicator pulses once twice or 3 times providing a specific trouble code that will help you quickly diagnose potential issues. For your convenience the codes are printed directly on the back of the tool. Bring your vehicle back to 100-percent and ensure proper functioning with the 192 12- and 24-Volt Diagnostic Relay Buddy from Electronic Specialties.