On the steering column near the bottom where your brake light switch is connected to your swing pedal support you should see a 2 piece curved wiring terminal with numerous wires that plugs together - pull it apart and take your multi-tester set on ohms and once you studied the wiring systemic of the turn signal switch and know what colored wires are L and R turn signal wires - connect 1 probe of tester on input power wire and the other on the output wire on what your have moved your lever to - if your meter shows the contacts are closing and complete your chosen circuit - if good you know so far that your brake circuit works and your turn signal switch is functioning -------- next move would be checking your wires that run along your frame rail - remember brake and turn signal share the same wire and since you have neither - leads to me to think you have problems with the rear wiring harness. Let us know what you find. THANKS!