This is my situation: We've had moisture problems in the drivers side light for a long time. Last week the HID light finally quit, and everyone suggested the problem was due to water in the ballast. So I bought a used but "tested" ballast off Ebay and scheduled the tech to come to my house, clean and reseal the light, and install the new ballast.

When everything was installed that light would not work. I don't have the ability to take off bumpers and remove headlights to work on ballasts, but I did swap the hid bulbs. The bulb that would not work on the drivers side was fine when I installed it in the passenger side light. So that eliminated the bulb. I also checked and actually swapped fuses controlling the lights. That was not the problem either. I have a voltmeter, but cannot get to the ballast itself since it is now installed in the headlight. Is there a method to check the voltage on that silver connector which attaches to the bulb itself?

I have a hard time believing this replacement ballast would be bad since the seller claims to test before shipping. But it appears to be that way. I don't have the ability to remove it myself. The tech said if I brought my car to his shop which is 35 miles away, he would not charge me nearly as much to replace this ballast if necessary. The Ebay seller wants me to send this one back to him and verify if there is a problem. But I can't do that because taking this one out first could cause me an extra trip to the shop plus labor charges.

So now I'm already out nearly $200 and still don't have a working light. Any ideas out there?

 

not sure if you know this, but people to lie. (ie ebay)

i would start with swapping ballasts side to side, you know the bulbs are good, and you know you have at least one good ballast. keep open about it, its possible its not the ballast.

On acura TL's (99 -03) there were 3 parts, bulb, ballast and igniter. no idea how the lexus is setup.

 

I took the headlight out today and found the problem. The tech who helped me with this last week connected the positive and negative leads to the ballast in reverse. I swapped the leads and boom....light works again.

This goes without saying, but if you ever take the headlight out its a good idea to connect everything up and make sure it works before bolting in and attaching the bumper cover.

 

I wonder how the headlight is holding up after the reseal? What sealant did you use?