My truck has the brake light on in the dash all the time..similar to what would be a park brake but the park brake isn't on.
What is my problem and how do I fix it to pass inspection?

 

There is a pressure differential/metering valve located near the master cylinder. You will see that there is a wire on it. When you step on the brakes, if the pressure to the front and rear brakes are not equal the metering rod inside the valve will move away from centered position. This causes the warning light to come on. If you disconnect the wire, the light will go out (if the problem is due to an un-centered brake light warning switch). If the light goes out you have a problem in the brakes. If the light doesn't go out you have an electrical problem (grounded wire, etc.).
So if the light goes out you need to find out if you have a brake problem. Obviously start by looking for leaks (are both reservoirs in the master cylinder full?). Drive the truck - do the front and rear brakes feel like they are working? You may have air in the lines that needs to be bled out.