Screwy lights

[RobL]

Question:

My 92 Sierra is having a wiring/light issue.
Left turn signal works fine. When I turn on the right signal all the lights blink. Even the license plate lights.
I checked and cleaned the grounds off the battery and taillights.

Any advice?

thanks

 

[Erik the Awful]

Check the right tail light bulb. It's either a single element jammed in a dual element socket, or one of the filaments has broken and is laying over on the other filament. There's also a less likely possibility that wiring from the socket is shorting between the two circuits, so check the bulb's wiring as well.