On a 1988 trans am when i turn the turn signal on to the right it works to the left the light comes on the dash stays on doesnt blink checked the bulbs they were good was looking for the flasher cant find it thought it was where the fuses are the big square cubes to the right pulled them out but same thing .

 

indicator lamp in the cluster staying lit solid with head or parking lamps on means that the parking lamp filament is bad or circuit for it is open

indicator lamp in the cluster staying lit solid with all lights turned off and turn signal on might mean the turn signal flasher is stuck/fused/burnt/junk

standard flashers are round plastic or aluminum

electronic ones are rectangular and plastic usually


however if one turn signal works fine then its not the flasher at fault

only one flasher runs both turn signals

another flasher runs just the emergency lights


to find them you need to remove your hush panel under the dash, its the large panel cover insulated under the entire driver side of the dash


look harder

good luck

 

you can also check the base, I had the same issue with an 88 Bronco.
Changed out both bulbs and turned out to be a base. Just fyi

 

Sounds like there may be a problem with the wiring to the bulb holders. The flasher will not opperate properly if there is too high a resistance in the bulb wiring. Check for damage to the wires, and especially where they attach to the holders. Also worth cleaning the contacts in the bulb holders as these can get corroded.

If you turn on the hazard lights you should be able to see which bulb is not as bright as other side, to give you a clue where to concentrate your search.

Good luck,

Si.