[header] How to test a relay [title] Consult the relay schematic or data sheet. [step] Relays have fairly standard pin configurations, but it is best to search for the data sheets to find out more about the number of pins from the manufacturer, if available. Typically, these will be printed on the relay. 
[substeps] Information on current and voltage ratings, pin configurations, and other information is sometimes available in the datasheets will be invaluable in testing, and eliminate most errors associated with testing. Testing pins randomly without knowing the pin configuration is possible, but if the relay is damaged, results may be unpredictable.