Just wondering... would you think that a simple 10A diode on the ballast power wire suffice to solve this issue? I may be oversimplifying things a bit, but from my limited electronics background that seems like an obvious solution. Maybe too much so, as I don't have a clue if a plain diode allows this short leaks of reverse current. Using a high quality ballast in the first place is a given, but so many OEM and big brand ballasts have failed on me over the years that taking all possible precautions is a good idea.Compared to other modules in the vehicle, the WMM has poorly designed power filtration and regulation, specifically, it has no reverse bias diode protecting the ground rail. Depending on the current load of the other devices in the shared ground branch, a defective/failing HID ballast can cause negative transients (positive with respect to Vbatt) on the ground wire, crossing that threshold and killing the chip. It need only reach 15v or so for a few hundred nanoseconds before the damage is done.