i have a problem on my 78 with my turn signals. when the headlights are on the parking lamps under he headlights dont turn on, then when i try to signal...nuthin. the front bulbs do nothing weather the headlights are on or not. the rear lights do signal but only when i manually move the turn signal lever up and down on the colum. also when the headlights are on the right turn signal indicator stays light up. i replaced the flasher and still same problem. should i replace the signal switch? all the fuses seem to be ok too. kinda confused so any help appreciated