2002 Malibu
 

When turn signal are turned on the opposite bulb glows dim. when pressing the horn the turn signal indicators glow dimly. The horn is intermittent. clock switch, turn signal switch, 4 way switch and body control module have all been replaced.

Found the problem. Cheverlot gounds things individually. There was a ground block on the drivers side next to the air filter.
The bolt looks like it rotted through. Anyway no ground for the horn or turn signal and the circuit back fed the lights.