check your air pressure gauge and make sure you are up to full pressure. A dim light usually means you have not built up to full pressure and/or you have a small or slow leak somewhere. I would make sure there are no leaks before driving this unit. Brake failure is never good. Driving trucks is what I do. Never leave a parked position with the brake light on or dimmed period. Try letting the unit idle for a few minutes to build up pressure. If that doesn't do it you need to either figure out why or have a mechanic verify.
