How can you tell if a relay is burnt?

Question

I can tell if a fuse is burnt, but how can you tell if a relay is bad?

Answer 1

Disconnected of course, apply power to the primary, and see if you get (or lose) continuity on the secondary.

Answer 2

tough question-how many leads does it have? if only two then you can do what was suggested except (the problem with someone telling someone what to do when they know-they assume you know also.

procedure with two connectors on the relay (a relay usually plugs in-a solenoid has screw attachments)
check continuity (if you don't know how to do that you really don't have any business doing this) with no power applied-it will be open or closed. apply 12vdc+ to one connector/attach another wire to the other connector

NOW-this is how you tell--TAP the other wire to the negative terminal of the battery (JUST TAP!!)
if the relay was closed and it's bad-then sparks will fly-if the relay is good then nothing will happen cause the power opened the relay.
if the relay was open then nothing will happen if it's bad (still open) if it's good then sparks will fly. what you are doing is shorting the + and - posts of the battery together. not a good idea-hence just tap----the better way would be to put a load into the circuit--do exactly the same except put a 12vdc light between the + post and the relay--then if the relay works/doesn't work the light will light up.

if there are more than two connectors then you can't tell anything without the wiring diagram-you got's to know what goes on each terminal-one will be hot and one ground the rest are unknown.

OH, and have fun