This may be a bad dual filiment bulb (1157,3057) dependin on year. Also the bulb may be in backwards. This is hard to do but is a possibility. If the signal indicator is on and stays on it is most likely a bad bulb. Otherwise you have a broken wire or a short in the lighting harness.
You have a dual-filament signal bulb somewhere with a bad ground. Turn the headlights and turn signal on. The bulb with the bad ground will go completely out at times, even though the headlights are on.
Check the contacts on the turn signal bulbs. Sounds like there may be a crack between the two contacts allowing the headlight/tailight voltage to cross over onto the turn signal contact. Hope this helps. josney613@hotmail.com
I realize that this is going to sound pretty dumb BUT....... Take the turn signal apart, totally, and wire brush all the connections very well. It sounds like you are getting a feed back through the ground. Do the same with the headlights. Put a little dielectric grease on the bulbs before putting them back into the sockets.
You have some problems with electrical connections. Most likely the ground wire of the tail lights. Also, the left light may be burned out or have a POSITIVE wire connection problem.
if your right turn signal does not work then it could be the switch if not then it could be a wiring fault! Could also be turn signal flasher or switch in steering column as stated above
Yea, check the ground in the front turn signal socket. You'll probably find that the ground connection is corroded or completely disconnected.
could be a bad ground
the left turn signal light on my ridgeline does not work but the right side works
I could not be sure about your particular problem, but I had to replace the Multi-Function and Turn signal switches in a 96 Lumina for similar strange problems of Brakes and signals not working in particular scenarios.
Check the bulbs. A failed bulb can often cause the signal to stop working on that side.
I would almost bet it's the directional light switch in the steering column. Do they not work when you step on the brake pedal also? I'd put my money on a faulty ground at one of the turn signal lights. Watch the bulb when you turn on the turn signal with the headlights OFF. If both filaments are glowing in any bulb, it doesn't have a ground.
Check the fuse for the wipers and replace the turn signal bulb.