tlxsess

I have been lurking on the forums here for quite some time and could really use the collective knowledge of everyone right about now. I recently replaced my low beams with some 6k hid's. I installed them using the upgraded relay harness i bought with them. My only problem is that upon startup of the hid's, they flicker for about 10 seconds then the flickering goes away and all is well. The flickering is random, not any sort of organized pulsing of any sort. When the hid's heat up, i can turn them off and back on and they dont flicker. I had lexus check my battery, and alternator and all is well. Is there any sort of extra step i have missed? Does the rx require a resistor on the unused headlight plug? or some sort of bypass for a factory system? I really appreciate in advance any insight or help I can get.

Kyle Harty

iTrader: (17)

Welcome to CL! It may be helpful if you can tell us where you got/what brand the kit is and how the relay is setup. It seems strange that the flickering always goes away after 10 seconds. Do both lights flicker or only one?

I hope someone else can help you more than I can since I don't really have an answer for you!

tlxsess

I purchased the kit from xtremehids.com. The relay is built into the harness I bought with the kit. The flickering is with both bulbs, mostly just with one or the other. its not a complete on/off flicker but like a pulsing flicker of random intensity. If any more info is needed please ask, I really appreciate any help. -Chris

tlxsess

btw... They are 55w ballasts/bulbs

striker_18

your car can only handle 35watts. Even with a relay, it will take some time to readjust the current to go via the relay harness you installed.
BTW, which kit do you have?

mitsuguy

iTrader: (2)

from the wording of his post, it would appear he upgraded standard lights to HID's, which, if that is the case, then that would mean he probably used an aftermarket ballast, and, he did use a wiring harness with standalone relay...

if thats the case, then he coulda wired in 100watt lights and the car wouldn't know the difference, so long as the relay and fuse he used was sufficient...

electronics are funny - their performance can vary depending on temperature many times... in this case, it sounds like one component on the ballast is not happy with cooler temperatures and does not output enough voltage to supply a steady startup voltage to the HID bulbs... when they get warm, or when its warm outside, then whatever component it is (possibly a voltage regulator?) is back to working properly...

two possibilities - 1) the component in the ballast spec'd by the manufacturer is not suitable for this application, or 2) there is a defect in the ballasts causing your problem... solution to #2 is easy - get them swapped out for properly working ones, solution to #1 is a little more difficult, and sounds more likely, as it sounds like both lights are exhibiting the same behavior, and thats that the manufacturer you purchased from skimped on parts and their ballasts are simply not up to par... the only fix if that is the case would be to go to a different / better manufacturer...

striker_18

well, there is a difference between cars with halogens with a 55w tolerance and cars with oem xenon headlights with 35w tolerance.

mitsuguy

iTrader: (2)

the only difference is what the stock wiring will handle... in his case, he replaced the stock wiring with a direct to battery wired relay setup, in which case, there is no stock limit to wattage anymore (unless you were to go so high as to melt the headlamp housing)...

striker_18

That is not true.
Just because you have a relay, any relay harness, will not be sufficient if you're drawing alot of amperage. It all depends on the tolerance of the harness itself. Afterall, there will be one or two relays for the whole thing. What relays were used?
BTW, aftermarket kits tend to be crappy.

mitsuguy

iTrader: (2)

The most commonly used relay for HID lighting systems is a 25 amp relay. I have seen this same standard, generic relay included in at least 4 different sets from different manufacturers.

But, bear with me for just a second, we're gonna do some math...

the smallest relay I ever recall seeing is 10 amp rated, those are quite small relays, and probably never included in a HID kit, but lets just say someone saved $1.99 by going to a 10 amp relay... Average HID kit is 35 watt, but, for this purpose, he has a 55 watt kit... no big deal... two lights, one relay, 12 volt system...

basic Ohms law states a very simple mathematical equation Watts = Volts * Amps

here, we have a 10 amp relay at 12 volts, so, that relay is capable of supplying:

watts = 12 volts * 10 amps or watts = 120

because we have two 55 watt headlamps, some simple math, means that they draw a total of 110 watts, under the max wattage rating of the small 10 amp relay... even if they did have to draw a little more power on startup, relays aren't rated on and on/off amp draw, they are rated on a thermal basis... draw too much power and it eventually melts the relay, not causes it to flutter or flicker like what is happening here...

just for kicks, his setup probably came with the 25 amp relay I already mentioned... do the math there, and it is capable of 300 watts... almost 3 times what his headlamps draw...

striker_18

You're forgetting length and wire thickness.
Also, your math will be fine if they were wired up in series but they are not.

mitsuguy

iTrader: (2)

you are determined to just not be wrong here...

55 watts is 55 watts... its total power draw... If it's not, show me the math where it would change...

for instance, a dual voice coil 4 ohm per channel sub may be rated at 250 watts per voice coil... you can wire it so it's a single 2 ohm load, a single 8 ohm load, or two 4 ohm loads... no matter how you wire it, it's still 250 watts per voice coil RMS rating... wanna really know something crazy - if you are feeding the sub 500 watts total, it doesn't matter if its at what resistance - its still going to use about the same amount of power at the amplifier...

for instance, an amp that is rated at 500 watts at 2 ohms will draw roughly the same amount of current as a 500 watt amp that is rated at 8 ohms... efficiency of the amplifier will have a bigger effect than what ohm the speaker is on the output stage...

back to the headlights...

lets say, just for a minute that they used the cheapest radio shack 18 awg wire you can find for the headlights... from the battery to the relay to the ballast, we're talking, what, 4 feet... 18awg is rated for 16 amps current draw... much more than the two headlights are going to draw... and we can talk about voltage loss as well... 4 feet of 18 awg wire, with a starting voltage of 14 volts (a healthy alternator should output 13.6 - 14.4 volts), there will be a voltage drop of 4%, or 13.5 volts, still way above idle battery voltage (a battery in good working order that is completely charged should be between 12.6 and 12.8 volts)... Just for a minute, I'll assume wire length is double what it needs to be, so, 8 feet... there we have a 7.9% voltage drop, and we are still at 12.9 volts, still well above idle battery voltage...

the reality here, as well, is that this is worse case... more than likely, his kit came with a similar harness to all the others I've seen which include 12 awg wire, which has a amp rating of 41 amps, and voltage drop over 8 feet of less than 2%...

mitsuguy

iTrader: (2)

wait, you don't have to do the math... I did it for you...

Resistance = Voltage(squared) / Watts
Resistance per HID ballast = (12.8 volts)squared / 55 watts
Resistance = 2.98 ohms per ballast...

wire it in parallel, we have 110 watts total and half the ohm value, so, 1.49 ohms...
because current = Square Root(watts/resistance)
current = 8.59 amps

Like I first said, well within nominal range of a 10 amp (small) automotive relay, and also well within 18AWG wire... in fact, you could even use 21 awg wire which has a rating of 9 amps...

striker_18

guy, that is for a conversion between one and the other. However, current passes through longer wires(6ft) and you still didn't take it into account.
Here is a simple website that will correct your flawed mathematics and understanding of electronics:
http://www.sengpielaudio.com/calculator-ohm.htm

And:


As a fixed current(non transferrable aka in the same circuit)

striker_18

Also, an rx330 has a 10amp(might be wrong but this is the norm in the US) fuse tolerance per low beam side.
Go buy a 10amp relay and try running it.