Nissan Repair: Brakelights on nissan will not come on., haynes manual, constant power

Question
I have a nissan 2001 frontier. I just had a stero put in about a month ago. My brakelights will not come on. the light on the cab will come on (or the third light) but the two brake lights will not. I replaced the brakelight switch, still will not come on. I tested the fuses they all work. Please help.  

Answer
Lavon,

The brake light circuit is constant power.  Check the wire feeding the brake pedal switch.  If there is power you have a disconnect down toward the brake lights.  If the circuit is not powered you will need to see if the radio has been tied to the brake circuit and is robbing power from it.  In rare cases I have seen vehicles where another wire had to be fed from the fuseblock to the brake switch to regain brake light function.  A Haynes Manual is a cheap way to get the wiring diagramk to make it easier to trace wiring.