I've been having an issue with the passenger side brake lamp (top bulb) constantly failing. I've replaced the bulb, replaced the whole lamp assembly as well. I put dielectric grease on the bulb contacts and still have the issue. I'm wondering if there is a high load on the circuit which may be causing this. How would I test this?

The bulb looks fine but doesn't work, I tried switching between left and right and the right bulb doesn't work in the left light, but the left light bulb works in the right.

Any ideas?

Thanks!