My son was born march 2006 and I was not present since then his mother has ran off, and I don't know where they are, I want to know if his birth certificate has been sighned by someone else, and how would I go about locating them.

You could try to go to the county recorders office where he was born and request the birth certificate, if your name is on it then you can obtain a copy. If you are not then you will know she didn't list you as the dad on it.

As for finding them, well that will be a lot tougher. You can really only do a search on persons by way of internet and the such to see if her name comes up anywhere. Or maybe contacting family members, if you know any (not that they will be real willing to cough up any info) but you could search surrounding areas to family members. Otherwise, I think that would be a job for a private investigator.

my son was born march 2006 and i was not present since then his mother has ran off, and i dont know where they are, i want to know if his birth certificate has been sighned by someone else, and how would i go about locating them.
I'm no expert but you can do a search on the internet for the mother... or if you know the state where he( your son) was born maybe you can call the department of vital records... and give them her name (the mother's)... that may work... I hope you find your baby but I don't think your name would be on the certificate if you didn't sign it at the hospital, because when a baby is born in most states the father has to sign an affidavit of parentage in order for your name to appear as the father on the birth certificate... that does not mean she got some one else to do it, it might have not gotten signed by a man at all...