
This 2005 Toyota Matrix came to me with an inoperative headlamp. It was not just the bulb, the socket it plugs into melted as well. I noticed that the socket had been replaced before and I wondered if perhaps that the circuit had a bad ground to cause this. I measured voltage drop for the circuit and it was within a normal range. Well apparently if you do not replace the head light socket with a high temperature rated plug it will melt like the one you see here pictured on the right. Especially with daytime running lights that are left on continuously.