Stereo & Electronics - window defroster circuit breaker is hot

hey guys so this morning i turned on my car and put on the heater and the window defroster and about ten mins later i came back to my car and my back window was still icy as if i never pushed the button. so i push it and all i hear is it clicking as i push it so i know about the circuit breaker because i installed power windows in my car and used it until i got a aftermarket one to use for my windows. so i got to make sure it was pushed in and it was so hot it gave me a really good burn on my finger.it was extremely hot. why is this? is there a major problem or should i just replace it? later in the day i took it out and it looked burnt on the blades,it is original. thanks guys

Those circuit breakers get less effective with age. It's cheaper and easier to just replace it with a 30-amp fuse. The fuse will plug right in to the same spot.

so that should do it? thanks man i appreciate it

Where is this breaker located?

Where is this breaker located?
In the fuse panel at the left end of the dash.

is there a good way to test it? My rear defroster hasn't worked for about two winters

is there a good way to test it? My rear defroster hasn't worked for about two winters
Not really. You could check for continuity but usually the problem is that they trip (open the circuit) too quickly...so it could test fine when cold but still fail to run the defogger long enough to do any good. If it is faulty then your power seats wouldn't work either (same circuit breaker). For the small cost of a fuse, it's best to just replace it and see if that solves the problem.