melted wiring harnes?!? o.O

[monito]

i've read several threads and heard from several people about melted wiring harnesses due to high wattage bulbs [like the APC super white high wattage bulbs].

My question is, How do you know if ur wiring harnesses were "melted?"
before i switched to SilverStars and now Halos, i used the APC super whites which were high wattage bulbs. One of the bulbs itself melted [well actually the tint melted off], but i'm not sure if my wiring harnesses were damaged.

[Tommy]

Do you know what something melted looks like?

if your harness doesnt look like that and your headlights work, you're fine.

[timebuilder]

First, you should know that wiring is designed to withstand the amount of power (volts x amps) that the system in question will normally use. Circuit protective devices such as fuses are intended to fail before the wiring exceeds a predetermined temperature. House wiring requirements are determined by NFPA, and automotive standards more than likely are a function of more general engineering guidelines.

As a wire approaches its intended service limit for power, it heats up. When that limit is exceeded, the insulation becomes soft and pliable, to the point that it can become so warm that the insulation melts off the wire. Normally, the proper fuse or breaker would open before the wire reaches such a temperature. Other times, the now-unprotected wire shorts out to ground (in a car) and the circuit protection device opens the circuit power.

Sometimes, high resistance in connectors and switches can limit the total power (by limiting current) in a circuit, and a load that you might expect to exceed the power capabilities of a wire can be limited by this resistance. That means that the device is not being fully powered as a result of the added resistance, and is permitted to draw less than the expected power, which could keep the power that is allowed to flow at a lower level.

If I were to upgrade lighting to a power level the sytem is not designed to support, I would add a new power source of heavier wiring and appropriate protection that would be controlled through a relay or solid state controller by the existing wiring.

Never try to increase the current rating of a circuit by replacing the correct fuse with one containing a larger element or higher rating.

[monito]

alright. thanks for the info! ^_^

[HomeGrown]

Originally Posted by timebuilder

Never try to increase the current rating of a circuit by replacing the correct fuse with one containing a larger element or higher rating.

For some reason, the thought of the REALLY old residential "fuseboxes" comes to mind, and how I've heard stories about people who replaced a blown fuse with a penny.

I don't know if that's one of those urban legends, or if that really used to work. Also wonder how many people got knocked on their asses by trying that.

[timebuilder]

When I was ten, we moved to a new house out in the country in Berks County, and I got to meet a very old electrician. As he checked our panel for a new addition my dad wanted to build onto the back of this 1800's farmhouse, I said to him, "is that stuff dangerous?" and he said in his Pa Dutch accent, "yah, sure is. Sometimes, people put a penny in there instead of a fuse once, an dey catch da ho house a fire!"

I wonder how many people, upon discovering how dangerous it was to have the penny there, decided to remove it from the screw base without pulling the main block above the glass fuses. Ouch!

[HomeGrown]

Probably a lot of old houses burned down for a penny. And like you mentioned, probably a lot of people learned about 110 either inserting or removing the penny.

Unrelated to the penny, but funny (in a really scarry sort of way)
At least he's wearing safety goggles.

[timebuilder]

I see another potential Darwin Awardee...

[monito]

will these plug-n-play adapters really protect the stock wiring harness when using high wattage bulbs?

http://www.kyousa.com/kyo_wh.html

sorry if this question was asked b4. I'm trying to see if i can get brighter [note: not necessarily whiter] lighting from 9004 bulbs. It's been several years since i used the APC high wattage bulbs, and i don't remember them being any brighter than the OEM bulbs or SS.

I found a 9004 --> 9007 conversion write up, but i want to use that as a last resort.

will a high wattage bulb produce a stronger lumen rating?

[timebuilder]

A higher wattage bulb "should" have a higher lumen number. The increase in lumen output depends on how efficiently the bulb converts electrical energy into light energy.

I'm not sure how these little harness adapters will help anyone. The power that feeds the harness adapter is still carried to the harness by the same, smaller, factory sized wiring. In a series circuit, current is limited by the highest resistance in the circuit, and any current flowing through the adapters will have to pass through the undersized factory wiring before it reaches the adapters!

What is needed is new power wiring form a higher current source, usch as a dedicated fuse link at B+, and operated by a controller that responds to the factory wiring.

[monito]

Originally Posted by timebuilder

I'm not sure how these little harness adapters will help anyone. The power that feeds the harness adapter is still carried to the harness by the same, smaller, factory sized wiring. In a series circuit, current is limited by the highest resistance in the circuit, and any current flowing through the adapters will have to pass through the undersized factory wiring before it reaches the adapters!

What is needed is new power wiring form a higher current source, usch as a dedicated fuse link at B+, and operated by a controller that responds to the factory wiring.

I was thinking the same thing about those adapters. I saw a couple of mentions about them in a few threads from a couple months ago, and was wondering if any one had any positive/negative feedback on those items.

So, the best thing to do is do a complete harness upgrade using thicker guaged wires, or do circuit upgrade as described here? http://www.danielsternlighting.com/t...ys/relays.html

[timebuilder]

It's perhaps not a first class technical writing exercise, but generally, it's the right idea when it comes to retrofitting high intensity lighting.

One note: I would not use the alternator output stud for the power taps. If you run a sufficiently large power wire (such as 14 ga stranded for most applications I can imagine) from the battery positive post where toyota has its large power fuses, you won't have a voltage drop problem. Plus, you get to mount the new fuses and relays nearby the stock units, creating convenience and a smart look.

Good quality solder techniques always make better joints than crimp connectors, as well. If you have ever seen a repaired Ford alternator pigtail, you will see the best practice is to crimp the sleeves and then use rosin core radio solder to flow the joints to a near-zero drop accross the repair. Then, heat shrink tubing covers the joint. The same techniques apply here.

Second, the diagrams appear to suggest new wiring coming through the firewall. To me, that's uncessary. The existing wiring will work very well for driving the relays. Relays draw a fraction of the power used by the stock lighting, and the headlight switch and hi/low beam switch will have no trouble controlling the relays. All new wiring should be in the engine bay, and installed in such a way as to be unobtrusive and professional.

Now, if you anticipate "undoing" this installatioon in the future and going back to the stock system, then buy two of those adapters and use them to access the stock wiring and to connect your new wiring to the new lamps. That would be a good use for the adapters.

[Zandro]

Putting a high wattage (85/90/100w) bulb into a headlight rated for 55w is ill advised, the end result will be a damaged/yellow reflector and possibly a damaged/burnt harness. I still don't understand why people disregard these warnings, last i checked high wattage bulbs + stock headlights is still bad idea. These high wattage bulbs are meant only for offroad use in auxilary lights with aluminium or other metal reflectors.

[HomeGrown]

I believe those "harness upgrade kits" are truly one of the most useless items I've ever seen.

Zandro made a point I was going to bring up, regarding too high of a wattage bulb. Even IF the electrical system is painstakenly upgraded to handle the extra current, the OEM reflectors and lenses may not hold up, and may warp & discolor eventually.

[timebuilder]

Yep.

If I were upgrading lighting, it would not be a simple bulb change with wiring. You need the complete show.