Heater Problem

Simple problem. Try to turn the fan on and it won't blow. Is there any way to tell whether or not it's the switch, motor, or core? I can't really tell if heat is coming out of the vents. Like sweeping out with fan, so... I'm thinking that the core wouldn't stop the motor.

Most likely the switch or blower motor.
Just use a voltmeter to check for power at the blower motor with switch on. If power is there, the motor is bad. If no power then check the switch... if power doesn't come out, replace the switch.

The cabin filter could be filled with dust and what not. The only problem is you have to take the dash out to get to it.

I Havin The Same Probem It Heats Up Fine And It Blows A Little Bit If Like It Would Be In Low And Smetimes Blows Fine For A Few Seconds..can Some 1 Help Me Plzzz

Check the wire connection directly below the glove box below the dash. Had the same problem. Grab hold of the wire and wiggle it a little bit. It has a slip fit connector that could have a bad connection.

I once had a lot of leaves build up around the blower that had gotten down in there from the hood. The leaves were blocking the air flow even though the motor was running just fine.
If your blower is running well, check to see that the airway is not restricted. If you remove the blower you can look up in there and see if anything is inside, but I believe there is a screen there blocking you from reaching in. I used a vacuum hose and reached down through the vents above the hood and sucked the leaves out...give that a try if it sounds similar to your problem.