I just recently bought a used 2007 Mazda 3 2.0 i and they came with aftermarket HID headlights. They both worked fine when I test drove the car on two separate occasions, but about a week later I noticed that they didn't come on after I had started the car. I flicked them on and off a couple time and only the right one or only the left one would come on. I restarted the car and the same thing happened but after a few more cycles of on/off they both turned on. Could someone give me an idea of what this could possibly be.
Thanks

 

I had put aftermarket lights in my '07 3 as well and had ordered them from http://www.theretrofitsource.com/. I ordered them in November or so last year. Apparently the balasts they sent out with the kit were no good and they ordered a recall on them. If you still have contact with the seller you may see if this is where they got them and then see if they can get replacements from the company which are free.

To compare, my experience was that the lights would fire up then would flicker from 100% power to 50% power. After a couple of weeks they then would no longer fire up at all.

 

You got bad ballasts or bulbs are low on gas. Happens every few years to mine