My RH signal will not flash if the headlights are on, BUT the arrow indicator light burns constantly with lights on, Turn lights off they both work perfectly, any ideas? I have change the lamps, but still don't work
Check headlamp grounds, black wire. If problem with headlamp ground, it may try to ground through the turn circuit? Just my opinion.
Yes absolutely check the headlight grounds but you shouldn't stop there, just keep going and check the marker and turn signal grounds and sockets, some sockets will show a slight burn mark right where the ground wire connects to the socket, check both fronts and rears lights.
It's the cheezy american bulb receptacle---the ground rots off, which then causes the turn signal indicator on the dash to light continuously when the headlights are on. Replace the receptacle with a new one and the problem will disappear.