Turn signal and headlights

flashers and turn signals have separate flasher and separate fuse.

I experienced the same symptoms that you described in your post on my 1986 mr2. I originally thought is was a relay or switch so I tested all of them. Every one of them check out functioning properly. After a number of days, I finally traced the problem to a burnt wire that was part of a socket that plugs into a horizontal blue and white panel under the dash on the driver's side just above the fuse block. Apparently the wire had come loose after so many years of bumps and other jarring movement and shorted inside the socket. I cleaned up the socket and wire connector, restripped the wire and put it all back together and made sure the connector was tight on the post. Now it all works pefectly.

It sounds like the relay is bad. It should be located in the fuse box. Replace and see if works.

you need to check to see which bulbs don`t work both front and back lights for the signal on the side it`s not working,you don`t say if any signals work or not if no signals work then you need to check the fuses under the dash on the driver`s side.now if it`s just one side then check the lights as mentioned above.if one isn`t then replace the bulb.if neither bulb is working then it sounds like the signal flasher is not working.turn on the hazard flashers and check the lights front and back.if all bulbs work then leave the hazards on and look under the dash for the flasher that is making the noise,this will show what the signal flasher will look like,then find the signal flasher on the fuse panel under the dash it should be located on the fuse panel.and replace

What may have happened is either the headlights wiring or the parking lights wiring somewhere along the wiring fused to the left turn signals wiring. Depending on if the turn signals go on when you put the parking lights on or the headlights on.

If the signals come on when you turn on the headlights than you only need to locate the light green wire that comes off the left turn signal harness.

Next follow that wire the entire way back to the firewall looking for another wire fused to that wire as you go.

If there are no signs of this you need to continue looking on the other side of the firewall all the way back to the turn signal and hazard flasher unit which is a black box that connects to a black harness located next to a grey harness behind the knee bolster.

But if the signals come on when you turn on the parking lights than you will also need to check the wiring from the rear left signal and follow that light green wire all the way back to the turn signal and hazard flasher unit.

This should fix your problem, but if not than your problem may lay within the the wiring between the turn signal/hazard switches and the turn signal and hazard flasher unit.

Also you may have a burnt circuit in the junction block. This block is where the light green from the rear left signal and front left signal meet. Don't have a description but if you cannot find it let me know and I will go out to the yard and look myself and let you know.

check if bulbs are burns

If ALL Wiring in Trunk is Good Then Its The SWITCH = Multifunction Switch<<

repalce the turn signal.headlight switch assembly

Try the fuse/breaker panel under hood, drivers side.