How to Test a Relay ?

I am chasing a crank no start issue and wanted to test the fuel pump relay under the hood. The 25A fuse is good , but how can I varify the relay is good ? thanks in advance

 

I'll bite. I can give you some basic information on testing a relay. You'll need an ohm meter and sufficient knowledge to understand what you are reading and two jumper wires with alligator clips on each end.

Does this relay have 4 prongs?

 

yes 4 prongs.
but not like the old school relays with 85 87 86 numbers on them.
they are the factory toyota tundra, small blue ones

 

Simple way to find the coil. The only two that show a resistance other than infinity. The feed to the fuel pump will show open until the coil is energized. You might be able to energize the coil with a 9 volt battery enough to test. Going to take jumpers or another set of hands. Once the relay picks check continuity across the other two terminals with your ohm meter.