I have a 1998 tahoe 4x4 and lately the flasher can has been going on by itself, just the ticking no lights go on. Signals work fine at regular times. I replaced flasher unit but it still does it at intermitent times. Seems to stop when I apply brake pedal. To weird

Your truck should have the "multi" switch. It's a combo t/s ,hazard and wiper switch all in one. It's probably gone bad.

And it ain't cheap either.