Simulating the load of a headlight.

[weirdlookinguy]

You guys may have seen my other thread about wanting to rice up my Civic with some HID/Xenon headlights. Well.... I couldn't resist. I went and bought a kit. I'll write about it in another thread soon.

I didn't want to run the xenon ballasts off the stock wiring for normal headlamps. Under normal operation, the xenon ballasts draw less power than standard halogen headlamps. However, when you first power on the ballasts there is an initial power surge that draws considerably more power than the stock wiring can handle. I didn't want to take any risks on blowing a fuse or overheating any wiring, so I installed my xenon lamps using a relay that's wired directly to the battery.

When I click on my headlights, it activates the relay. The relay then provides the xenon ballasts 12v directly from the battery. This way I won't pop my headlight fuse during the initial power surge when you first turn on the ballasts.

The system works great. However, after running the new xenons for about forty-five minutes, my Check Engine light came on. I haven't been able to hook it up to a OBD2 scanner yet to see what the codes are. But my gut feeling is that because I'm using a relay to power the headlamps, and this relay only connects to ONE of the headlamp connectors, there is no power draw through the stock headlamp wiring and this is making my ECU think that something is wrong.

Is there any way I can simulate a light headlamp load? (say maybe 1 amp @ 12v). Resistors?

[ratdude747]

Re: Simulating the load of a headlight.

are all the neons one one ballast?

my instinct would be to have an even number of ballasts with equal load and split it between 2 relays. (One per connector)

try that if you can..

for load simulation, yes, resistors.

[weirdlookinguy]

Re: Simulating the load of a headlight.

They are not neon. They are xenon bulbs, more commonly known as HIDs (High Intensity Discharge). Completely different. There is one ballast per bulb, so two total. The relay harness I am using only plugs into one of the original headlamp connectors. Running two relays along with their accompanying harnesses would look like shit under the hood and is completely unnecessary.

Ratdude, you have very little real life experience with cars. I need someone who has at least rolled their sleeves up and spent several hours of quality time under the hood.

[Junk Parts]

Re: Simulating the load of a headlight.

WLG don't jump the gun on your check engine light. The new headlights might not play into the situation at all. You need to get those OBD2 codes out of the car before you try to fix it. They are very helpful. I'll give you a case in point. My high mile Suzuki threw a check engine light on me two years ago. It has all sorts of electrical trinkets on the engine. The car still ran fine. I had no idea what the issue was so I took it to Ammco Transmissions for the free code read that they offer there. The code came out as EGR flow. I removed the EGR valve and found that the ports for it in the intake had become clogged with carbon. With the help of a screw driver and a drill bit held by hand I was able to chip this mess out of the intake. That is all it took to fix it. Back in the spring it threw a check engine light again while I was on a long trip. I revisited the EGR valve thinking it may have become clogged up again. It was clean as could be. When I got home I got the codes and this time it was for "oxygen sensor heating." Installed a brand new used one from the boneyard and that fixed it right up. Some ECUs have a hardwired Check engine light map built into them. The light will go on at a given milage no matter if any parts have failed or not. My 84 Prelude was this way. It had a screw on the back of the instrument cluster that was used to reset the light. AS I remember , the screw had holes ABC and D it could go into. If the light came on and the screw was in position A you just moved it to position B. This reset the light for another 80,000 miles. Now if your problem wasn't just a timmed light coming on the check engine light wouldn't stay off using this reset. I don't think your newer honda does it this way. There is a guy on this forum called "Hondaman." I would think that he knows more about this than I.

[Krankshaft]

Re: Simulating the load of a headlight.

First off these are not xenon headlamps they are metal halide an arc tube type lamp. They have no filament. Don't know how they got commonly referred to as xenons. Whenever I hear xenon I think of a filament type lamp.

An arc is struck between two electrodes vaporizing the metal halide mixture and emitting light. The arc is struck with a series of high frequency high voltage pulses this is a called the pulse start method which ionizes the argon gas (which aides in starting) and allows the arc to strike. This is when that higher current is drawn.

These pulses are high voltage low current. Because when ever you step up voltage with a transformer you lose current in exchange. More current is drawn from the battery to get your higher voltage.

I hope you fused your direct link to the battery. If something ever went wrong in the ballast it would have a lot of unchecked current to possibly start a fire.

As for the headlight I'd pull the code before coming to any conclusions.

If you did need to calculate a load resistor at your specs use ohms law. I = Current, V = Voltage, and R= Resistance.

R= V / I
R= 12 / 1
so R= 12 ohms

Then use joules law for the wattage:

P= I * V
P= 1 * 12
so P= 12 Watts

So you'd need a 12 ohm 12 Watt wire wound resistor. To supply 1 amp at 12 volts. Obviously the math is not needed here since it's all into 1 but it's good to know for more complicated calculations.

If you wanted to simulate the true amperage of the original lamps. You'd need to find the amperage to plug into ohms law. To do so divide the wattage on the bulb by 12 volts to get the amperage. So if the original low beams were 32 watts 32W / 12 = 2.6 amps.

[weirdlookinguy]

Re: Simulating the load of a headlight.

Thank you JP and Krankshaft, for useful replies I can actually use.

Damn, every online place I visited refers to them as Xenons. I feel rather ignorant now. My goal when I speak about car stuff is to be educated and know what I am talking about. As you can see, I failed here I'm trying though!

Krankshaft, there are two harnesses, one is the 12v relay and the other is a sensing harness for my high/low beams. Both are fused.

JP you are right. I need to go pull the codes before I start jumping to conclusions. I have a computer telling me exactly what is wrong and yet here I am going about this the hard way .

I'll let you guys know once I pull the codes. I will probably have to abandon this thread and start a new one.

[Wizard]

Re: Simulating the load of a headlight.

Is the HID headlights OEM? If it is generic, pull them out and put original headlights back in. I absolutely do not like HID at all. Generic HID is not designed properly and HID requires specific reflector housing. And all the issues you are seeing is the one of reasons that kit is not done right.

Cheers, Wizard

[PCBONEZ]

Re: Simulating the load of a headlight.

A cost effective dummy load to simulate a headlight load is a headlight.

.

[Krankshaft]

Re: Simulating the load of a headlight.

I believe I voiced my opinion about kit HIDs and mentioned what Wizard said about the reflectors in another thread. Figured there's no point in going through the DOT approved reflector stuff again. I believe even the OEM housings focus the light too sharply and don't diffuse it enough.

We have full inspections in NJ every 2 years I'd get a fail if I tried using one of these kits. Although it seems they will be cutting back soon and only doing emissions tests every 2 years now to save money. More people may get away with it here now due to this fact.

[weirdlookinguy]

Re: Simulating the load of a headlight.

I had a feeling you guys would disapprove. The kit I bought is not insanely bright, it is white not blue, and I aimed the headlights down a bit so as to not blind everybody. The last thing I want to be is one of those assholes with torchlights instead of headlamps.

[weirdlookinguy]

Re: Simulating the load of a headlight.

I may end up getting rid of the damn things and selling them on CL. I just found out that speeding tickets recently went way up here in Commiefornia. Not sure if that's true or not but the last thing I need is for my car to draw some jackass cop's attention with bright ass headlights. The fact that it's a sporty looking Civic (read: rice rocket) is bad enough. In fact less than a month ago I had a cop tail me for a few blocks. I'm pretty sure he was running my plates. This has happened four times since I bought the car.

I should have just bought a truck.

[Junk Parts]

Re: Simulating the load of a headlight.

No you bought the right car.