Last week I started to have a problem with the turn signal in my 2002 Tahoe Z71. All of the lights would flash rapidly, and the side I was activating would burn the brightest. The rear Cyclops light also flashed. Immediately I replaced the flasher under the dash, that didn't work. Armed with a lot of information, I decided to order a new turn signal and install it. THAT DIDN'T WORK EITHER!! 
After some addition trouble shooting, I discovered that the problem ONLY happens when the parking lights (or headlights) are on. That is even weirder!! I have removed EVERY relay and fuse related to those lights. It doesn't fix it. Although... when I removed the fuses for the front parking lights, the problem slowed and seemed better. Then I removed the rear parking lights, that ALMOST made it stop, but there was still a faint flashing of the other turn signal flashers on the opposite side. PLEASE HELP!!!
After some addition trouble shooting, I discovered that the problem ONLY happens when the parking lights (or headlights) are on. That is even weirder!! I have removed EVERY relay and fuse related to those lights. It doesn't fix it. Although... when I removed the fuses for the front parking lights, the problem slowed and seemed better. Then I removed the rear parking lights, that ALMOST made it stop, but there was still a faint flashing of the other turn signal flashers on the opposite side. PLEASE HELP!!!
