Signed as 'Grantor' on home equity loan. What is my responsibility?

Six years ago my wife took out a home equity loan. Her credit was scored higher than mine so the loan was issued in her name only. I was required to sign as 'Grantor", which was explained as needed for them to file a lien on our house for her loan. As the grantor do I have any responsibility for repayment of the loan should my wife default on payments? I'm sure that the lender could foreclose as I technically agreed to that by allowing them to lien on the house. Would my credit be subjected to a charge off because of non payment of a loan that I did not sign for? Since the loan origination date in 2005 my Florida home has decreased in value by $140,000. I have no equity and I'm out of equity by at least $70,000 counting the 1st mortgage and the equity loan. The interest only home equity loan balloons in 4 years; the $93,000 balance becomes 'payment due in full'.