Your cables are just a steel wire inside a hollow coiled sleeve so spray the "BLASTER" directly onto the cable the whole length what you can reach, and it will get to the inside where the rust is and free your cables up, like Don said,unless their kinked, or the cables are froze on the carb. Check the butterflies on the carb. make sure its freed up. You can also spray your heater/defrost cable. Keep a towel handy because the cables will drip if you spray to much, especially inside the cab.
Good luck
