Replaced headlight ballast working backwards

[DNiles]

I’m new to the forum so first off Hello everyone. 

I have a 2011 Ford Edge Limited and a month ago I started having problems with my right headlight. When it rains that headlight will go out and usually stay out until it dries. I was told that it was a bad ballast that moisture was getting in to the ballast itself. I ordered a ballast for it and installed it and it works backwards. When the switch is on the light on that side the light goes out and when the switch is off the light turns on. I contacted the dealer and they sent me a new ballast and it does the same thing. Any suggestions would be helpful. I’m assuming it is an polarity issue but I am unsure how to resolve it. Again any suggestions would be great. Thanks everyone.

P.S. It is a 3 pin connector.

[Sage]

 Welcome, sorry I cannot help on the question. 

[jmr061]

Could be a ground issue.  May want to check the two grounds on the headlamp connector and where they terminate on the frame.

[DNiles]

Thank you for your response. The grounds look good. I’m kinda stumped because when I put the old ballast back in the light works fine unless I’m driving in the rain. I put a seal off of one of the new ballasts on the old ballast today to see if that seals it up and keeps it from going out. Whether it works or not it doesn’t explain why the new ballast causes the light to work opposite of what it should. Is it possible for the polarity to be reversed? I’m not sure. I did notice that the two new ballasts had 1 digit different on the model# I’m assuming. Mine has a dash 7 the new ones are dash 5. The manufacturer says they are the same. They are all Osram brand.