I owe the IRS money from a business I owned that has since closed. Do I have to sign over my refund check or can I just set up an installment plan?

I believe the IRS would accept an nstallment plan, or eventhey can barter to a reasonable figure..

You can request for short time payment agreement or installment agreement.

Make a Short-time Payment Arrangement with IRS. A short-term extension gives a taxpayer up to 120 days to pay. No fee is charged, but the late-payment penalty plus interest will apply.

Apply for Installment Agreement. A monthly payment plan or installment agreement gives a taxpayer more time to pay. Taxpayers can apply for a payment agreement by filling out Form 9465, Installment Agreement Request.
For details, Your U.S. Tax Return: IRS Due Date April 15, 2008: For Those Who Can't Pay the Tax Due in Full

If you owe money to the IRS, they will CONFISCATE any federal tax refund and credit it towards that debt.

Yes, you can set up a payment plan. Just make sure you stick to it.