The Final Answer to your Dim Gauge Cluster

I'm going to attempt to further lodge my foot down my throat.

The most common cause of melted sockets is corrosion in the socket. Corroded copper has a much lower temperature threshold and dumps out the heat at a faster rate. For a simple test take a strip of copper and a strip of corroded copper and apply a small amount of low current voltage to them. Get 2 stopwatches with lap timers. If you do lap stops at when they each feel warm to the touch and turn off the power then stop when they both feel cool the corroded strip should heat up much faster and cool off much faster.

Then recall that plastic is a terrible thermal insulator.

 

Wait a minute we're getting a little deep here, there is almost no copper in the sockets(actually I believe most have a alloy similar to brass), so isn't really enough metal to act as a heat sink and transfer(conduct) the heat... The plastic overheats from the bulb and it melts...

Earlier this year I repl the third brake lights in one of my vehicles that uses 921 bulbs, electrical condition was perfect but the sockets were slightly melted... Wasn't enough of a issue to be concerned with so I repl bulbs and put it back together... Those bulbs are mounted vertically, base down so heat is actually directed away from the socket, still near the bulb's glass(not contact) the sockets were discolored and melted... With the horizontal mounting inside the cluster, I cant imagine there not being issues... I'm sticking with the 194 in my stuff...

 

I suppose maybe the direct sun exposure on those third brake lights can't help either, right? I mean if it's already perhaps over 100 degrees in that housing before you even heat it up with the bulb I could really see it baking up good if you're sitting in traffic a lot...

 

Uh, anywhere that you have electricity flowing through metal generates heat. Flip off a light in your house, pull out the bulb and stick your finger in the socket, it will be hot. Also, you can't really direct all of the heat away from the socket no matter how you position the bulb. So bulb heat + connector heat = melted socket. Add in some sunlight baking it up a bit. Yea I see that. Especially if any corrosion has built up in the socket.

Again, corrosion is the most common cause of melted socket. If you liberally slather all of your sockets with dielectric grease it will help because it will absorb quite a bit of the heat.

 

Not unless it's undersized there is NO heat generated from the socket or wiring... Heat in the socket is transferred down through the bulb, it's not generated within the socket... If what you are saying is true, there would be home fires on every block daily because of electrical issues...

Now if you plug in a couple 1000W heaters into a std 15A circuit(#14 wire) and assuming the breaker doesn't trip(some yahoo repl the 15A with a 25A because the smaller breaker was tripping), then yes there will be heating in the wiring, outlets and switch... Exactly the reason many wiring fires are started...

The cords on many high wattage items are slightly undersized and do get warm, usually it isn't a issue but I always keep a watchful eye on such items...

 

No it's because the NEC calls for correct insulation to be present. I have the 2012 issue of the NEC (national electric code) on my computer. Its really big. Home fires from electric bulbs were REALLY common when they first came out with them. Also why we don't use cloth wrapped wires anymore, the slightest corrosion creeping into them causes fires.

I'm not really sure why we are having this debate. I'll look up the full electrical specs on the bulbs he's using and do an analysis of their heat profile if you want, but you have to look up the characteristics of the sockets used in our cars. I need the exact mix of the plastic and composition of the connector landing strips inside the socket: alloy, thickness, width. I have the electrical characteristics of most alloys on files easily accessed and if I don't have them I can get them easily. It's part of my job.

Not really sure why we are arguing this so much. It's kind of a silly topic.

 

So, what's up with this DIY rear defogger you mentioned?

 

PM sent, I don't want to hijack this thread any further.