Hey everyone. First off, if I posted this in the wrong forum, I apologize. I think it qualifies as problems as fixes (even if it is PREVENATIVE fixes )

Anyways, when I bought my '02 TL Type S, the one foglight glass had a complete hole in it, and the other one had a large crack in it. Sunday I ordered two new assemblies and some 3000K bulbs for it (halogen). Well the bulbs came in early (thankfully, since I get to address this issue before possible installation) and they saw they are 100 watts. ("100W" on package). I know most stock replcaement bulbs run either 35W or 55W. So obviously 100W is twice that.

My question is: Is that too much for the wiring? Will it burn up my harness? Most people say yes, but my reason confuses me haha.

How can a bulb draw more power that it's getting power? In other words, if the harness only supplies the bulb with x amount of wattage, how would the 2x bulb be a hazard if only x amount of power is supplied in the first place? Isn't that like saying running 100W speakers will blow your radio/speaker wiring if the radio only puts out 52W per channel? The speaker reasoning logically aligns with the bulb reasoning...but I think something is messed up with my understanding of how this whole thing works.

Inputs anyone? Thanks so much in advance!

 

Also just thought of this: if the wattage is too high, won't it trip the fuse? if they light up, then I blow a fuse, that's a good safety net for knowing the bulbs are too hot?

 

They likely WILL draw more current than the circuit is rated to carry. Chk. the amp. rating of the fuse supplying that circuit. Then I = P/V. Filling in the known values yields a current of approx. 7.4 amps (I used 13.5 volts & 100w). That is the approx. current draw of one of the lamps so x 2 = approx. 14.8 amps draw for just the 2 lamps. You have to add the potential draw of anything else on that circuit to approximate the total current draw. These are approximations and are affected by variables such as wire size, available voltage, etc. See http://www.the12volt.com/ohm/ohmslawcalculators.asp for some useful calculators for figuring such things.

Hope that helps.

 

NO, Thats not how that works.


100w is WAY to hot for those small housings. You will melt them.

 

Alright, my physics is coming through. (sorry if i seem to be talking to myself, but the more info I give, the clearer my case is? haha)

So 100 Watts. Watt is a measurement of power. Power = Current * Voltage.

Simple algebra gives us 100W + Amps * 12V
Giving us only 8 and 1/3 amps. That's well below the fuse limit (isn't the fuse a 20 amp fuse?) soooo the fuse idea is a bust.

I did; however, find this: http://www.rowand.net/Shop/Tech/WireCapacityChart.htm
New question to add to the list: anyone know what gauge wire the foglight harness runs?

edit: And would it be a pain to upgrade the wiring?

 

None of that matters as the housing is plastic and TOO small for the heat that will be generated by the bulb.

 

Oh. Dang I feel dumb. Well looks like I need to get some new bulbs. THIS TIME, to be safe, what is a safe wattage? 55 or 35?

DDM hid conversion kits have a 35W option...i could just get legit 3000K HID's. Heard ddm is great stuff. $45 is cheap haha for lifetime warranty. thoughts?

 

Do Yourself a Favor and Get HIDs if you Want more Lm Output!
I think 55w HID is OVERKILL for Fogs since they dont light Up pretty far anyway... 35w HIDs will work just fine No need to Worry about Melting the Housing or Anything, Just Make sure to Install the Relay Kit for added piece of Mind.

 

Is that really necessary, do you think? Esp if it's only 35W, would start up put that much of a drain on it?

 

The problem is with the mechanical switch. It may not be able to handle the full current going through it continuously. Using a relay to switch current is always the safest.

 

There hasnt been a Single Issue or Accident with not installing the relay kit In our TLs! but Understand that the OEM wires arent able to support the Amps that the kit draw! A normal bulb will drain about 1 to 5 Amps and the OEM Cable is somewhat 25AWG or More! Each Ballast take about 11 to 13.5A when Fired (In an Instant) Up so it may be Too much for OEM Cables!

Its your Choise/Car so its up to you, A Relay Kit is only 7-10 bucks Anyway and its Super Easy to Install some vendors even throw it up for free.

 

THIS....

35W is good enough....55W your pushing it....100W is just killing it....

if it sucks more current it will comes with a higher rating fuse....but 100W will 100% melt ur housing....

 

Alright, thanks guys! I'll be sure to get the relay kit with it (I had forgotten about fire up current draw). With that, I'll probably start my car thread! Thanks for all your help.

 

FTR, DDM HIDs only draw ~ 6 amps at start up, and 3.4 amps at operating temperature. It might be possible for anyone else considering this to skip the relay harness, if you look up the current draw from the stock bulbs (I don't have it on hand).