What is your current rate on your loan? I can do cash-out refinances down to 500 credit scores with 24 months on time payment history up to 85% of the homes value. Perhaps I can help you with both the rate on your current loan and to get you the cash you need. My name is Jake Johnson and my email is firstname.lastname@example.org. Talk to you soon!
Unfortunately since home equity loans are not sale-able to Fannie Mae, Freddie Mac, or FHA, approval guidelines and credit requirements are even more strict for this type of product. And in today's lending environment a 500 credit score will not qualify for any type of mortgage even under the most lenient of programs. No lenders really want to work with borrowers who pose a credit risk. As a matter of fact, every lender I know of requires at least a 680 credit score for a home equity/improvement loan
You may want to check with the city/county you live in to see if any assistance is available to make improvements. If that doesn't work, then the best advice I can give you is to work on boosting your credit scores into the 600-620 range, then maybe applying for an FHA 203k rehabilitation loan.
Best of luck