Possible flasher?, I would take another look at all the bulbs that work in parking mode and in turn signal mode on the left side. After you see where each one is, then do the same on the right. I think you'll find you overlooked one or didn't check them while they were in the parking mode. A turnsignal/parking bulb has 2 filiments, one for each situation. Post you results.
It is definitely because a bulb on that side (left or right) is burnt out. I had a 1990 Cutlass, so I know.
check the bulbs on the side that does not flash, it's quite possible one is burnt out
One of the bulbs is burnt out. Replace the bulb.
Your "turn solenoid" is defective.
Check bulbs Replace turn signal flasher
One or two front turn signal bulbs is busted. Check your front turn signal bulbs and replace it.
If the turn signal bulbs work but just do not flash, replace the Flasher Relay.
One of the bulbs are broken, check all of your turn signals.
one or more bulbs for the turn signal have burned out....try replacing the bulbs
One of your turn signal bulbs is burned out. Either the front or the back.
If the bulbs are good buy it just will not flash the flasher relay is defective. Replace it.
Replace the signal flasher relay assuming you have physically seen front and rear, left and right signal bulbs flash.
You may have a "ground loop" problem on the left turn signal. Check the ground wire at the front and rear signal bulbs.
Usually it's because one (or more) of the signal bulbs is burnt out. It is also possible that the turn signal relay is faulty.
One of the bulbs likely burnt out. When the indicator light on the dash remains solid (does not flash) it means that a turn signal or marker light is out
You have to replace front and rear bulbs.
one of two things, either the flasher or the signal relay EDIT: Um, NO. You have a bulb out. It can't flash outside, it's dead. Inside, electricity is still flowing, so the interior bulbs work twice as hard to keep up with the current. Check all your light bulbs and/or sockets.
check the bulbs one is burned out
Bad ground Bad switch in steering column
If the turn signal bulbs light but will not flash, the flasher relay is defective, replace it.
If the bulbs check good, replace the flasher relay.
Most likely because one (or more) of the signal light bulbs is burnt out from the fast flashing side. Check them first, replace the burnt bulb, and they should go back to normal. If there are no burnt out bulbs, then you might consider replacing the turn signal relay.
More than likely the Flasher Relay is bad. If the bulbs are lit but will not flash it is definitely the Relay. This can also indicate a bad bulb on one of the lights on the side that does not flash.
You may need a new flasher.
Did you install the correct bulbs? Replace the flasher unit ------------------------------------------------------------------------------------- Yes! Flasher unit. Y-THINK-Y
Try replacing the turn signal flasher