If throwing parts at it didn't cure it, you'll need wiring diagrams and a test lamp. If you can't get power at that flasher, back to the signal switch. Some of the aftermarket signal switches are junk. Check that turn signal current goes into it and does it come out on the selected left or right wires. There have been several threads about end users tweaking the little metal contacts in switch and/or cancel cam to make them work as they should.
