Brake/signal/flasher, left side, not working tried bulb/fuse 2002 not 03

The turn signal, brake light, and flasher are on the same wire. I would take a circuit tester light and trace the wire to see where you lose the voltage. It would likely be where two wire looms connect. I would look at the rear connector first.

I have to think the problem is inside the turn signal switch, a poor internal connection. You know the brake signal first goes through the turn switch before it goes to the bulbs. That is why the brake lights and rear turn signal lights share the same filament in the bulb, and the same wire going to those lights. The only difference is the turning side light is affected by the turn signal flasher, causing blinking, while the other side- the non turning side-does not go through the flasher relay, but straight to the bulb from the turn signal switch. Change your turn signal switch and I believe you will solve the problem. Let me know, okay?

you have a short in one of the light sockets or a worn wire from the wiring harness. could be the flasher assembly. are the turn signals different bulbs from the brake lights? Does using the brakes blow the fuse? (Rear lights or brake light switch on brake pedal). left or right turn signal blowing the fuse will tell which side has the short. 4 ways only, replace the relay.

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.

Brakes are generally not fused seperately. Have u check the bulb in the left side.

you need to check the bulbs holders and wiring even a blown bulb will not blow the fuse and an damaged wire or bulb holder will as it will make earth and live go together. there are also fuses for left side and right side turning lights cannot remember rating think they are 10amp.

Yes, it does have a flasher, although it may be a combined unit with the hazard flashers relay. So you hear the clicking of the flasher relay? That seems to indicate the relay is working properly. Have you checked the bulbs and the turn signal fuse? Any turn signal bulbs light up anywhere, front or back?
How about your brake lights, do they work? Your car may have separate, stand alone turn signals in the rear, but many American cars use the same bulb and same filament on the bulb for the brake lights and turn signals. If your merc is like this and the brake lights work, then the bulb must be good.
Turn on the hazard flashers and see if all bulbs work and flash at each corner of the car. This would be the same bulb as for the turn signals. If they work, it could be a bad turn signal switch, may even be the flasher relay somehow malfunctioning, and in a few cases, a bad hazard switch can affect the turn signal switch. Check fuses and bulbs first. If you have any type of body control module that controls lights and other accessories, you may have to investigate that. I know I'm not being very helpful, just throwing out a few suggestions. Good luck.

Maybe a relay or fuse is bad or the wiring to it.

But you said that the third brake light works.

So the brake switch must be ok.
Turn signals would be the flasher or wiring to it.
CIRCUIT PROTECTION Fuse Block Fig. 1: The fuse box is located under a cover at the lower left instrument panel — 1987 Voyager shown
The fuse block and relay bank is located on the driver's side under the lower instrument panel. The fuse block contains fuses for various circuits as well as circuit breakers, horn relay, ignition lamp thermal time delay, and the turn signal flasher. The hazard warning flasher is mounted into a bracket below the fuse block. The individual fuse and relay locations can be found in the wiring diagrams at the end of this section.
is bad.

check to see if the emergency flashers work if they do its its either a wiring problem, bulb, or socket the bulb fits in. if it does not work than the flasher is the problem. it is located underdash on driver side in the kick panel( to left of the brake pedal) it is a blue or grey sguare relay looking plug. if it is factory flasher it will say flasher with the part # on it. it should also say toyota on it. good luck

If the fuses are good and the front and rear bulbs are good, change the flasher for the turn signals, even tho the right is working. If that doesn't fix the problem, it might be in the turn sgnal switch on the steering column.
If both bulbs are good for the backup lights and fuses are good, then the backup light switch, which is screwed into the side of the transmission has to bad.