HouseCallAuto 5/27/2010No, it cannot be the brake light switch. If the bulbs that are not lighting up are good or you have replaced them then the cause is likely a bad turn signal switch. Here is a diagnostic to be 100% if you want to do it:
> 1. Test B+ at the White wire, at C202 by the steering column, pin A6 with the brake applied.
2. If OK, test again at pin A4, the Green wire.
3. If no B+ at A4 but OK at A6, replace the turn signal switch.