Turn signal flasher location 2004 impala

It should be in the hazard button, You have to pull it out and replace it. Try the junk yards they dont cost alot.

There's usually a different flasher for the hazard lights (4-way) and the turn signals. But, for either flasher to go bad is very rare. If the flasher is bad neither right nor left signal will work. If only one side doesn't work, it's not the flasher.... then I'd really check the bulbs first.
And sorry, I don't know where the flasher is.