[Shotimes] OT: HID's and Headlight Relays?

[clubairth@bellsouth.net]

No you won't get 90 V back to the headlight switch! The ballast might go 
open or short to ground but an 12 VDC automotive headlamp system will not do 
this. Look at how it's wired.  Just like the HID capsule is ignited at 23K 
+/- 1K volts. That won't get back to your headlight switch either. But the 
HID headlamps are labeled with a high voltage warning sticker because that's 
where you could possibly come across the high voltage.
.
.



> >There is no way for 90 V to get to the headlight switch!! It's only 12 
> >VDC
>>until you get inside the HID assembly and the ballast takes over. So no it
>>won't put high voltage on your headlight switch wiring!
>
> While this may not be the typical failure mode for HID modules (been 
> mentioned already that they tend to short internal to the voltage coil), 
> I've seen enough power supplies short back to the input via regulating 
> components, feedback loops, and even shorted windings to know that what I 
> stated is quite possible. Knowing this, I cannot consciously give advice 
> to anyone to  preclude their own safety.
>
> David