So I'm running ebay hids in the rallycar (they are awesome, in case you were wondering), but one side went dead recently. After a little trouble shooting, found the fuse to be blown (15amp). Now, these only draw 35 or 55w, so I mean they don't even draw 10 amps. Stuck another fuse in there, popped instantly.
Nothing has changed on the car recently, and AFAIK, the light was working earlier in the week. Could the ballast be shorted internally? I can not imagine how the wiring could possibly have got damaged, so the ballast shorting is the only reason I can think of.
What say you GRM?
Probably a faulty ballast. I can't imagine much else. Shorted somewhere internally or maybe wires.
I have had HID ballasts fail shorted before. Not on cars - this was a house light - but the ballast instantly blew the breaker when it failed. One minute on - next minute pop and the lights go out.
So it's very likely the ballast is bad. You might try unhooking the ballast and seeing if the fuse still blows. If so, then it's a short. If not, it's the ballast.
I would say the ballast.. cheap chinese things don't don't seem to hold up well. DDM Tuning is the only brand I've heard good things about for reliability.
+1 for DDM. They also offer a lifetime warranty.
If you have each side wired separately can you swap ballasts and see if the fuse still blows?
Cheap HID kits usually blow the ballasts pretty quick. I put a set in my 2009 WRX from a reputable Subaru vendor (no longer in business though) and I blew a ballast within 9 months of installation. 
HID-equipped cars are starting to show up in junkyards. Pseudosport built a kit for his old 2007 WRX using ballasts that came out of a Nissan or Infiniti. I still have my kit. I might find some ballasts and toss them in my 3 at some point if I get bored. This could be an option for you if ballasts are indeed the issue.
I used a cheap HID kit on the Ti.. it lasted for years.. only ballet issue was the tape came unstuck from the back of the bumper after a couple of years and it dragged on the ground and died...
+1 for DDM Tuning. I had a set and loved them. Never had to use the lifetime waranty either.
for trouble shooting, unplug the ballast and see if it blows another fuse. if not, try the other side in its place
+another on DDM tuning HIDs. I've had them in the same offroad lights on two trucks now with a few hundred miles offroad and no failures yet. At least not from the lights. My fuse has some corrosion so occasionally I have to sand it down but that's not part of the DDM kit
I used to sell cheap HID kits. I always ordered 1.5x the number of ballasts I needed because they'd tend to go.
I have DDM too, worked pretty well ballast wise, bulbs died on me and they required I send them in before warrantying. They did send me 2 new ones as promised so they would match, just took awhile. Would suck if they were in my low beams but they were my fogs so no big.
There was a big bruhaha when DDM announced they would be getting out of the HID business, something to do with Customs seizing their supplies at port for breaking the law (I guess they were claiming the HIDs were for aquarium use as they are not legal to import for vehicular/road use?) anyhow it looks like that got resolved as they are back on the website selling HID kits and bulbs. Another issue that came to light was people claiming DDM only stocked 3 tempuratures of bulbs and would ship them as whatever you ordered. IE 5000k bulbs being shipped as 5000k, 4300k and 3000k yellow bulbs, even though there was an upcharge for 3000k yellow bulbs. Who knows.
I hear good things about VVME on ebay, my buddy put 2 sets of those into his camry mains and fogs, also lifetime warranty but not sure of the warranty process if it's even worth anything, esp if you have to ship the returns to China at your own cost.
Anyway, for either brands/companies I'd buy two kits to have a backup in case I need to use the warranty. They are cheap enough and the concensus seems that most cheapo kits come from the same few factories anyway. I've been leaning towards TheRetrofitSource as it seems they contract the factories and impose a higher standard of quality for their morimoto branded stuff.
Skip eBay entirely, use these guys. No affiliation, just a satisfied customer 
The Retrofit Source
