Left brake and left turn signal not working on tow vehicle

No Diodes, I wired the lights for towing separately. The problem is in the motor home. All the lights work properly on the motor home, but I'm not getting a left turn signal or left brake like at the plug. Right turn, right brake, tail lights, all work on the toad when plugged into the motor home for towing. I've check the back of the plug, and it's fine, I'm not getting power to the plug for left turn signal and left brake.