Good luck Colleen trying to seal your lights
, but if you are able to get this to work, please share it as this is very difficult to do. I've tried repeatedly and had some success over the short term but eventually leaks
develop. Dust (I travel back roads extensively) always gets in and often water as well.
Both bulbs out on the same side would initially suggest a problem with the fixture itself or a problem with the ground wire for this fixture.
If the fixture is rusted, I would start there. Cleaning the rust off may make it work temporarily and indicate the problem. Once rust is initiated, it will come back when moisture is present and moisture is usually present from numerous sources. Best course of action is to replace the fixture and avoid future problems.
Check to see if you've lost the ground to the fixture buy running a piece of wire from the chassis to the metal part of the fixture. If this is the problem, running this wire should make both bulbs of the fixture work.
You can check for power to the fixture using a multi meter, a test light
or a bulb in a socket. Make sure you have a good ground to the chassis. You can ensure your grounding point is good by first testing a light
you know is working.