2004 Suburban 1/2ton 4x4. Left turn signal works fine. Right turn signal (front / rear / dash) does not work.

When you step on the brakes, right turn signal (front / rear / dash) comes on solid. So if I am making a left turn and braking, the left turn signal will flash and the right turn signal will come on solid.

At times, when braking, the right turn signal will only come on if turn signal lever is up. At other times, whenever you hit the brakes, the right turn signal will come on solid.

Brake lights work fine.

Factory trailer hitch wiring, seldom used, looks fine.

This started a couple of days ago and at first right turn signal would flash and then go solid when brakes were applied.

Troubleshooting ideas welcome???