It took several different trips to several different mechanics to figure out what was causing the light to fail. One finally did. The issue was that the metal components designed to make contact were not making proper contact. This resulted in insufficient conductivity, which caused overheating. Over time, the housing began to melt due to the excessive heat generated from this poor connection. That mechanic had finally figured it out, but did a poor job of fixing it. So that repair didn't last long. We took it to another mechanic, Christian Brothers, and tried to explain what had happened but they insisted on their own diagnoses and expensive tests before finally declaring they couldn't fix it. My friend's mechanic finally just rewired it altogether for us, and that repair has lasted these last 4 or 5 years. The only downside was having to look at the dashboard light for that headlight.