Help an Idiot Use a Multimeter

[panthro]

I am reasonably competent with most things but electronics is beyond me. I've got a 40A circuit breaker in my car that I suspect is faulty and therefore the heating in the car is not working (Mk3 Supra). I bought a multimeter but have no idea how to check if this CB is faulty or not. Any help would be greatly appreciated!

 

[panthro]

Thanks guys, I set it to #3 to measure resistance. It buzzes when you connect it to each terminal on the CB, which means I guess current is getting through?