All my turn signals work, but when I activate the 4-way warning lights, only the right front turn signal blinks. The book says there is only one flasher; so, what gives?
The problem is in the multi-function switch located in the steering columm. It can be cleaned and re-bulit. But it is tedious. Recommend getting a salvage yard unit. Take it apart and clean and regrease the contacts. Use the same kind of silcone grease used on spark plugs.
OBTW, it would be a good idea to give the model year of your car. In this case, it doesn't matter.