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      12-15-2011, 12:10 PM   #32
Rotary Rasp
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Drives: 2009 E92 335i 6MT
Join Date: Aug 2008
Location: SoCal - Torrance

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Quote:
Originally Posted by ********* View Post
Well the reason why you need to buy special ballasts is because most of the time, people are upgrading from halogen to HID.

Many halogen fixtures have a PWM signal on the power line to control the output of the halogen bulb. This PWM signal will kill HID ballasts because the signal outputs a square wave to control the bulb's brightness..... basically it turns the bulb on and off rapidly. So fast, you cannot see it. But the ballast does and they are affected by this....this is why sometimes people get flickering HIDs. The PWM frequency is slow. A faster PWM frequency will allow the ballast it ignite the bulb initially, but then sometimes it will shut off. When the PWM frequency is set to the fastest setting, the ballast will act like it's operating normally, but in reality, the componets inside are seeing constant fluctuations in voltage....it doesn't help that the car's electrical system is very noisy either.

This is where coding comes in. You can code the car to xenon which will eliminate that PWM signal.

Now I'm not sure how the OP's setup is going to last since you can't remove the PWM signal from the angel eyes....at least to my knowledge. He coded out the errors in step 7, disabled the "soft illumination" feature (which is most likely a PWM signal) in step 6, and disabled the dimming (also a PWM signal, it's in the code name) in step 8.

But nothing was done for the way it lights the bulb continuously....again I'm not sure if you can code angel eyes to xenon.

I do know you can alter that PWM frequency so that the PWM signal is so fast, fluctuations in voltage are minimized, but that just hides the problem and a ballast failure in inevitable. It can be a week or 6 months before the ballast fails, but it will ultimately fail.

Also OP, the reason why other setups have a wire going out of the housing is because they most likely are grabbing power directly from the battery or another 12v source that does not have a PWM signal on it. Then a relay is used to light the ballast, triggered by the existing angel eye power wire, and powered by the external 12v source.


You can code the car to increase the PWM duty cycle to 100%. It requires one more step which involves coding non-standard variables into the NETTODAT file. It's not hard. I found that disabling the dimming was enough for the ballast to work. However, if people have concerns about running them at 80% duty cycle, I will gladly provide information on how to completely disable the PWM for the angel eyes (100% duty cycle) - it takes 3 more minutes.
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