I have a regular mortgage and prime equity line of credit, which is called the second mortgage can I get a third mortgage?

Today.. Highly unlikely a lender would do that. Few years back... maybe, today, highly unlikely.

Really depends on how much equity you have in the property. Its more likely that you can get a refi of your first mortgage. But if you have little or no equity its going to be near impossible to get any more money on the property.

Remember a mortgage is a secured loan. Its secured by the value of the property. The lender wants to know that, if you default, the property can be sold to recoup what they lent.

And a third mortgage would have to pick up any scraps if there are any left after the first and second mortgage liens are satisfied. Definitely far less secure from the lenders perspective. And as such... they would be far more hesitant to make such a loan, and the interest rate would be much higher on one as a result.

May be able to refi, on first or first and second. Depends on equity. But a third not that likely