I have a 91 honda accord I am checking the main relay when I turn the key it clicks like it is working but when I pulled it out it smells burnt how do I find out if it bad

Bench testing main relays is somewhat useless, since you can't simulate the intense heat they are subjected to in use. Cold PCB solder joints are the usual problems, which only materialize under load. I recommend replacing these problematic components every 120,000 miles or 10 years, whichever comes first.