Q&A

 Master

Do BOTH rear turn signals work when you look at the rear bulbs while you test them not just the dash indicators? Do BOTH rear flasher bulbs work when you look at them again not just the dash indicators? Do the same with the front turn signals and flashers. If they both work then check your 3rd brake light. There is a diode ( a one way electrical gate ). Try unplugging that, not just removing the bulb(s) and see if there is a difference. The flasher mechanism IS the relay. The flasher/relay would effect BOTH lights. If the above does not work , then check your brake light circuit grounds. A bad ground or weak ground can cause some weird things. If this does not work, then go to www.alldatadiy.com and subscribe for 1 year ($26) and you can download the wiring diagrams for your Chevy and start tracing the circuits. Best of Luck!