Ive got a 99t&c limited. The brake lights work fine but if i turn on the headlights the brake lights stay on constant. I checked the fuses under the dash and replaced the brake light switch also. Any suggestions where to look next would be great. Thanks

 

The tail lights and brake lights run through the same bulb in the rear lights. I think you should check the rear light circuitry to make sure you havent got a short between the tail & brake. Also remove the rear light assemblies and see if the circuit board or connections need a clean.