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Hi, I'm a newbie, I spent 15 years as a mechanic at a Chevrolet dealer, performing misc elec, HVAC, Trim, windnoise and waterleak repairs. I replaced the headlight bulbs in my daughters 2003 Trailblazer with a set of the 8500k Xenon bulbs that sell on ebay. The first set lasted about 6 months until one burnt out. The wiring at the back of the connector turned brown, I did'nt think anything of it. However about 2 weeks ago I replaced them both and in 2 weeks both the bulbs and the connectors have melted. I replaced the connectors tonight at 13.00 each. My daughter likes these bulbs but I cant think of anything that I can do to use the bulb she wants. I have these bulbs in my car and in my wifes van and both of them work fine. I came to the conclusion that the only difference is my daughter's truck has Daytime Running Lights. I don't think these bulbs can stay on all the time without burning something up. I need to devise some way to use these bulbs without burning bulbs and harness's up. The only thing I can think of is to either disable the DRL's or devise some type of heatsink for the bulbs and wiring. Does anybody have any ideas other than going back to OEM or GE Sylvania's super bulbs ?
 

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Welcome to the site! Glad to have more skilled folks joing up with other skilled folks!

What we're talking about is electricity through a circuit. I wouldnb't think that it matters much that it's a bulb. If it's melting the connectors, then there is a weak wire in the mix that can't handle that much current. Isn't that right? Maybe someone else knows more about this issue.

What are the specs for the lamps for current? How many watts/amps, etc?
 

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The OEM bulbs are 51 watts for low beam and I think 65 watts for hi beam. These bulbs are 80 watts low beam and 100 watts hi beam. Supposedly since they are Xenon gas instead of Halogen they are not supposed to run any hotter than an OEM bulb. I don't even think the Chevrolet Shop Manual will tell what amperage is. (possibly a secret, if Chevy told us they would have to kill us----LOL). I really think it has something to do with the fact that with DRL the lights are on almost all the time (well at least anytime the engine is running). None of the other vehicles in my family have DRL but they all have the same type of bulbs without any ill effects. I do know that a poor connection will alwaysincrease resistance and therefore create heat. But these thingsaremelting on the 12v hot side of the blade inside the bulb housing, What the hey ?
 

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I would say a heavier gauge wire is in order. It doesn't sound like it's heat from the bulb so much as amperage draw through too thin a wire. The Easiest way to tell would be leave one normal bulb in one side, and the bulb in question in the other side. Start the vehicle, and let it run for about 10-15 min with DRL on. Put your hand behind the headlamp assy, and feel the heat. The reflective coating should be absorbing most of the heat, and you shouldn't feel much. You could always use a digital thermometer, if you have one to check the temps. If the heat is in the wire only then you have high amps in an inadequate wire.
 

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I agree with the heavier wire concept, a larger wire would act as a heat sink to pull the heat away from the connector. I just know that it probably would not be wise to go crazy large possibly from 20 gauge to 18. The fellow at the dealer where my daughter picked up the connectors with the harness' said he had a Trailblazer SS and he had the same problem with bulbs but went with a HID system which is a little out reach financially for my daughter.
 

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I wouldn't go crazy large. You could also go with a double wire on each leg of the original gauge. All you'd be looking to do, is alleviate the resistance in the wire. Using a larger gauge wire is one way, but tagging on a second wire on each leg will work as well too, and keep the harness just as flexible. It isn't really providing a heat sink, because the heat will still be there if it's a bulb heat issue. With long runs of wire, or too thin of wire for the application you create resistance.

Think of it like a river. With 3000gpm flowing. If the river is narrow the flow will be rapid, and tend to erode the riverbank. If it's wider, the flow will not be as rapid, and is less likely to erode the bank away. the flow creates resistance, which causes friction the friction erodes the bank. It's similar to the wire, only the resistance in this case causes heat.

HID lights are out of a lot of peoples financial reach.
 

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Discussion Starter #7
Thanks for all the useful input. Some of the automotive sites that I've been to, most of the people on them spend more time fighting with each other or get completely off the automotive subject. So I'll frequent this site and hope that I can help supply some helpful suggestions from my automotive experience.
 

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We look forward to your participation on this site.:biggrin:
I'm sure with your background you'll be able to help out a lot.

Even though it's a little late now.... Welcome to the club!!!
 

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I agree. If you have stuff melting, you need to increase the wire going to it. Never thought about running two wires, but that would do the trick I suppose.
 

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Dangerous stuff

OK, let's review ohm's law:
From: Wikipedia

In mathematical terms, this is written as:
, where I is the current, V is the potential difference, and R is a constant called the resistance. The potential difference is also known as the voltage drop, and is sometimes denoted by E or U instead of V.


There is also a "temperature effect" that states:
When the temperature of the conductor increases, the collisions between electrons and atoms increase. Thus as a substance heats up because of electricity flowing through it (or by any heating process), the resistance will usually increase.

In other words, the circuit is designed to run a bulb, specifically rated for the same circuit. When changing the bulb to a higher wattage, you alter the resistance of the circuit. Similar to, but not akin to using a higher amperage fuse in a shorted circuit.

In the end with your choice to use 'better looking' lights you run the risk of a fire hazard. I'd stick with the rated bulbs, rather than bothering with modifiying the circuit. Unless of course you want a car-b-que.:biggrin:
 

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I would say a heavier gauge wire is in order. It doesn't sound like it's heat from the bulb so much as amperage draw through too thin a wire. The Easiest way to tell would be leave one normal bulb in one side, and the bulb in question in the other side. Start the vehicle, and let it run for about 10-15 min with DRL on. Put your hand behind the headlamp assy, and feel the heat. The reflective coating should be absorbing most of the heat, and you shouldn't feel much. You could always use a digital thermometer, if you have one to check the temps. If the heat is in the wire only then you have high amps in an inadequate wire.
Newbie to this forum so here goes the first post and I may be sticking my neck out here. Yes I know its been awhile since this post was submitted, however as I was reading the posts being a virgin here and decided that this may help someone down the road.
I agree that increasing the wire size at the area of the current problem will correct the burn in that area, HOWEVER... it will move the problem to a different area unless you increase the wire size in the entire circuit as well as the switch that operates the headlights as the circuit is designed for the lower wattage lamps and the heating problem is going to move to the area of smaller size when you increase the wire size at the plug. I wouldn't want you to have a fire under the dash.
A way to change this circuit and do it at low cost is, Increase the wiring to an after market relay designed for fog lamps, run the same wire to the battery from the other side of the relay and the control to operate the relay is the wire that currently operates the headlights. This will allow for the increased current draw and will still operate the headlights in the OEM fashion without straining the OEM wiring or switches.
 

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Here is a kit to beef up your headlight wiring. End result is brighter headlights.
 
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