Hey guys,

I bought a set of relay harness to hook my HIDs to the battery, but after getting them, I am starting to think twice about using them.

First of all, there's one cable that runs between the battery and the relay. That cable itself isn't all that big, and it has to handle ALL the power that travels to the two HID kits. I won't know if the cables are actually bigger or not unless I cut it open and look at how much element is inside and cut open the stock harness to compare.

Second of all, I am worried of the quality of this harness.

I "borrowed" a IR heat sensor from my lab and used it to measure the temperature of the stock harness from when it's off and when I first turn on the light. No difference in temperature.

Has anybody with a tC and with a HID kit actually ran into trouble because they weren't using the wiring harness?

 

Never thought about NOT using the wireing harness because I don't want to even risk frying my factory socket... sry buddy. I'd use it.

 

seems like a risky move to do.

 

Like you, I am just being careful about it as well. Having been a TA for a few engineering labs, I have seen more than enough cases for me to be weary about chinese made cables and connectors.

 

i say use it, have that piece of lighting insurance and doesnt really hurt timewise to install.

 

I replaced that sad looking strip of cable with a thick one I got from my lab that is rated to 400A. Take that!

Installing it later today, it's too hot outside.

 

your HID's would never in the world draw 400A. Do you know much about electricity? i.e. watts = volts x amps? Do you know ohms law?

HID's are what 35watt bulbs? Yes they do draw more current at first to illuminate but they actually draw less current than our stock bulbs. The only reason to beef up your wiring is for that initial current jump to illuminate the bulbs. So lets say for numbers reasons it draws as much current as a 60watt bulb when the lights are first turned on.

so 60w = 12v x a?

you would then divide your watts by your volts to get amps

in the equation above the current draw would be 5amps.

Even at 120w it would still be only 10amps. So 20 total for the 2 lights and you are using a 400A cable? why the excessiveness? Is that cable like double 0 gauge? lol not trying to be mean just trying to understand your point of reasoning. If I were you I would build my own harness, I trust my own work more than an aftermarket brand.

 

Just because I went and took the beefiest cable from my lab and you are calling me not knowing electricty? I have a BSIE and minor in EE ok. The reason I took the 400A cable was because I went into my lab and there's a big roll of it. My research paid part of it, might as well as take a little of it.

Duh, I know that HID operates at lower wattage, but I do my calculation based on being safe on ignition of the bulb. Where I take the 13.2 rated voltage and the 10A rated Imax. Two sides, so multiply it by two. That's still a few hundred watts combined. So I am 20x over the top, but hey, it's not gonna hurt.

Look at your ballast. Mine is rated Imax at 10A, so yes, it's excessive. Some ballasts hav Imax rating of 20 and 30A, and they are all made by the same manufcturers just with different labels. So god knows what is it.

I would also trust my own work as well but I am too busy this term getting started on my MS thesis because I want to get out of school asap. Sorry, but your message does look a little offensive. And yes, they are HUGE!

 

I wasn't trying to be offensive, I even stated that, so sorry if it seemed like it

I understand being busy, as going to school, working, and doing my own work on the side for others gets in the way for what I want to do and time for other people as well. Good luck with your project, let me know how it goes. Could you do some testing to see what the current draw of your ballasts actually is? It would be interesting to see if they follow their ratings.

 

I am planning to do it as soon as I get my prof's new controlled enviroment unit is installed. That way I can even test the effects of temperature fluctuation (and use testing the setup as an excuse). Last time I tested one was with a Bosch ballast that had a Imax of 30. With the power source set at 13.xv, calibrated to 3x.xA, it was still flcikering like crazy on startup. Needless to say, my professor laughed at me and told me it's in chinese units.

 

if hids only draw 20 amps on start up then they shouldnt be frying stock wiring. if im not mistaken stock headlights use a 20 amp fuse and unless scion messed up with their wiring it should be able to take it. if these ballasts pull 30 amps you should be popping fuses.

 

read the sticky and search and you'll see several scion owners who burned their factory harness because they thought they knew it all about our beloved tc and the headlight wiring.

either use an aftermarket one or build your own or risk being broke from all repairs that need to be done afterwards.. not to be mean of course

 

I am not sure what fuse they take, but you are right on that.

Weird thing is that the cables and connectors always seem to melt before the fuses pop.

 

I would def. USE THEM!

I put some cheap aftermarket blue bulbs and it melted my factory harness, so i went and instald some thicker after market wring harness and better bulbs and it did it again!

Dont risk it, better safe than sorry.

 

Are you talking about HID or halogen bulbs? You used Luminics didn't you?

 

Lol idont know. all i know is that their are cheap lights in a plastic case. Owell it happend and it got fixed.

 

^ thats because you used ricer bulbs. any bulb that is coated blue is a true ricer bulb! they have to run at a higher wattage to compensate for the blue coating taking away from the brightness.. so, thus make them brighter so they are equal brightness to factory bulbs..

but w/ all those people who melted there stock harness, it depends on the bulbs.. ricer bulbs draw more ALL the time, while HID's only draw for like 5 seconds (hight startup current) after than, then its all good.. so basicly, the stock harness isnt gonna fry in 5 seconds of "spike" current. over many many many startups, it could, possibly could, wear on the wire making it brittle and evently go, but it should never melt or fry in my own experince.

but even still, how can you melt wires but not blow the fuse? that is the real question. my thought or theory is that the fuse is at 20A for the same reason we are having this conversation.. "spike current" at startup.. even though there halogen, they still spike at turn on just not as much as HID.. so, my guess is the wire, stock wire that is, can handle the spikes of stock bulbs from start up and thats why the fuse dosent blow, that and there "slow blow"... so when your running those ricer bulbs, your realy close to that 20A but not beyond it and the wires cant handle the extend current draw.. where as it can handle the spikes, just not the constant heavy current.. any thoughts? if what i just wrote makes sense...

 

It does, but now i just wish that i could have met you 2yrs ago for that info. lol

 

ive been running the 8k from Oznium for about 7 months or so now, no problem yet. just dont turn your headlights on often tho lol

 

If you were going to run them off your factory harness the passenger side is a thicker gauge than the driver side harness. But if you already have the after market relay harness you should definitely use it. The factory headlight harness will only switch the relay on and if anything was to get damaged it would be the harness from the battery to the hid kit, that extra part that you bought. It would bypass your factory wires totally and get power straight from the battery, saving any factory equipment. If it fries you won't be any worse off than when you started. And if you are really worried about the materials it is made of and got all of that schooling in electronics you should be able to wire up a relay harness yourself with all of that spare wiring you have in your lab, that is what i did in my car anyway. That way you can give your self the peace of mind you are asking for with this thread.