My front left turn signal will not operate and I have replaced the bulb. All other light bulbs are working on the vehicle. The right side turn signal works fine.What do I need to check or replace?

Check front signal bulbs.

Generally speaking, symptoms of a bad or failing turn signal bulb are usually the culprit...in your case, either it's the front left or rear bulb. Varies for different vehicle makes...common signs include:

1. turn signal light staying on solid
2. or blinking very fast
3. or either sides of the bulbs stop blinking altogether.

To test this, make sure you reconnect everything you disconnected.
Turn the left signal light on; go to the front of the vehicle, is the turn signal bulb illuminated? If it lights up, even though it is not blinking obviously the bulb is okay. If it doesn't, replace it- problem solved. You'll do the same procedure for the rear turn signal Is that lit up? If not replace the bulb and the problem is solved.
Another common failure is when the turn signal blinks really fast, same procedure as mentioned above.
If both bulbs for the left side and right side illuminate but don't blink, the problem is in the steering column turn signal switch.
If the left or right side blinkers don't work properly at all...then check the integrated hazard warning/turn signal flasher relay- that may be defective; again, that's usually the case if both sides of the signal light don't work.
If you are blowing any fuses related to the flasher system, you have an electrical overload in the turn signal circuitry.

Has the vehicle been in an accident on the left rear side. First check the bulb to be sure it is not defective, trade it out with the side that works properly to test. If the bulb works well then My thought are you may have a shorted wire. The turn signal flasher works by heat build up within the flasher the heat is caused by the load of the bulbs, the load heats the metal spring causing it to open the circuit then as quickly as it cools down the circuit closes again lighting the bulbs.
There is also a possibility of a defect in the turn signal mechanism on the steering column. The turn signal switch on many models does three different things on many models that use the same bulb element / or bulb for brake and turn on rear of vehicle. It controls the circuit for brake light by sending power both left and right side rear when turn signal is in neutral position then when turn signal is in left turn the switch cancels brake light power to left side rear and supplies flasher power to left side while maintaining brake light supply to the right side rear, and so on opposite when the right turn is chosen on turn signal switch. The turn signal indicators on the dash normally run off the same circuit as front turn signal bulb only which is also controlled by turn signal switch. Front has turn signals but no brake light.
I think there is an additional load on the left side rear turn circuit and it could be either a wire that is shorted or the turn signal switch if the same bulb element is used for both functions.
Often times if trailer lighting is connected the flasher will also blink a little faster because of the extra load of additional bulbs.

was the correct bulb used? this sounds like a single function bulb was used NOT the bulb that will light with the headlights and ALso produce turn singles

it's the grounds if they're both flashing fast it's definitely grounds take a test light and see if its got power goes through the test light grounded to the frame and if the light comes on then it's definitely your grounds

have you checked the bulbs front and back. to see if they work, bulb check. then it sounds like you might have a bad signal flasher that only works the left side and not the right side. or if a bulb at the front or the rear gets bright but not the opposite bulb on the same side then you may just have a bad bulb or socket or power to the socket when doing the bulb check.

I don't believe it would be a bad ground for just one light. It could be a wire, a socket connector, or the bulb socket itself. See if the wire has power at the socket when signaling left, with key on. If there is power, probably a bad socket or connector. If no power, check for power coming from flasher-the wire going to front left, or driver's side. If you have power from the flasher, but nothing at the socket, the wire has probably broken.
Good luck.

Fast flashing occurs when one bulb in the circuit has failed. If the back turn signal bulb is flashing, then a front bulb has failed. Try replacing any remaining burned out bulbs (there may be more than one at the front and/or the back - if the right side is ok, check that side of the vehicle for locations reference). Be aware that the problem can also be one or more bad turn light bulb socket connections - in some cases, dielectric grease may have been added inside the sockets to inhibit corrosion. This is not usually a problem, but to be sure, make sure they are clean and free of corrosion.

Gday mate, we had a problem with another late model vehicle similar to that, the bulb that was put into the reverse light was not exact brand product ( ohmage was slightly wrong ) and fowled up computer, correct bulb in place and disconnect battery to reset K A M ( keep alive memory) problem solved, BEWARE, some vehicles cannot have KAM reset except for dealer computer tethered reboot , just try putting the factory correct bulb(s) in and see how it goes, geoff. hope this helped.

What you speak of as to the left blinker doesn't flash, yet the instrument cluster shows the green arrow (to the left), and yet that and the left turn signal lights do not flash, appears to be a simple burned out bulb. If one of your left turn signal bulbs are burnt out, then the #552 Flasher Unit in your fuse box is NOT the cause. It's the "Amperage" not being correct to the flasher unit. Place the parking brake on and start your vehicle. Put the left turn signal on and check to see ALL the bulbs are illuminated for the left turn signal. If you find one bulb that is not illuminated, then replace the bulb. It should be an 1157 bulb, but in the front it could be a 1157 Amber bulb dependent on whether your turn signal lens is clear or yellow.

If you still have difficulty finding the dead bulb, turn on the right turn signal and see which bulbs are illuminated and this will give you an idea as to which bulb on the left side isn't working, or turn on your Emergency Flashers which will turn on both the left and right side lamps and see which bulb is not lit up.

I hope this Helps,

~00 Buck~

"Still living on the Right Side of Dirt..."