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 (http://taxipay.blogspot.com/2008/04/irs-due-date-april-15-2008-for-those.html)

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.