Back running light on rt doesn't come on with headlights. Brake light works though

Have you checked your fuses. Brake lights and running lights are normally powered by different fuses.

Yes. Fuses have been changed. Doesn't the rt n left running light operate off same fuse? I think they were changed n both bulbs were changed too

I really don't want to take it to shop if. It's something simple. Don't know why but the door locks went out first then both running n brake lights went out. Replaced bulbs n fuses associated with those n also put a new multiswitch in. Now everything so far works but the one running light

There are two lights in each of the rear assembly, Simply take the whole assembly off and put your directional on and have someone check the brake lights and running lights. the running lights and brake lights should be a double element set up. Replace that bulb if needed, wear rubber gloves so as not to put body oils on the bulb, it will prolong it's life. Good Luck