OEM incandescent license plate bulbs singed the socket!

An OEM rear license plate illumination bulb burned out after 5 years on my 2012 hatchback. When replacing it with an LED version I was surprised to notice that the gray plastic socket was discolored and slightly melted around the base of the bulb. So I pulled the other license plate illumination bulb out and found the same situation (see picture). I have now replaced both bulbs with slightly lower wattage but brighter and whiter LED versions, and hope that the total heat dissipated will be enough lower that the plastic sockets will not deteriorate any further. But especially if you have an older Gen III with the OEM incandescent bulbs, you might want to check those sockets at some point. On the 2012 and newer hatchbacks with the two rectangular plastic access panels for the license plate bulbs, this remove and replace operation is quick and painless should you decide to change the bulbs.

 

I watched a YouTube video for the license plate bulb replacement where those rectangular lids appeared to be absent and the gentleman removed the entire plastic interior cover of the hatch to get at the bulbs. Thus I was unsure which Gen III years and models had those rectangular pop-out access lids and which did not. My bulb lasted 75,000 miles and almost exactly 5 years, so I cannot complain, but I prefer the illumination of the LED type of bulb and rather hope they will last longer.

 

Jimbo, I installed those in my front parking light sockets and they certainly improved the parking light illumination in front! I did have one fail after about 2 years (?) though, but I bought them in a package of 4 so no problem. Have you replaced the amber front side marker lights with LEDs by any chance?

 

Not sure, but on my vehicle, the bulb sockets on both sides of the license plate holder were about equally singed, which makes me doubt a defect and simply suspect the high heat output of the OEM bulbs (hence the warning). Incandescent bulbs typically waste 90% of the input wattage as heat, but the heat can be dissipated by radiation, conduction, or convection, so the bulb and the exact design of the socket and enclosure can play a role. The LEDs typically have less wasted wattage overall, but my understanding is that they dissipate much less by radiation and commensurately more by conduction particularly at the base of the bulb, so I'm really just hoping that the net bottom line is less heat being put into that gray plastic socket. I'd rather not have to replace that socket at the next go-round!

 

Mendel: Another possibility is that the incandescent bulbs burn both brighter and hotter just as they are ready to burn out (increased resistance and energy consumption) , and that is the process that was melting the license plate bulb socket. We use parking lights on all days except direct sunshine because our gray Prius is almost invisible on cloudy days on gray pavement. If correct, this implies that other folks who are replacing burned out OEM license plate bulbs should have noticed the same melting, at least if they were in the warmer southern parts of the US.