I have an 89 mustang 5.0 with factory a/c. I broke my belt the other day and am now in a pickle. I was looking at the diagram under the hood which shows the direction to route the belt and i see what is called an air pump (not to be confused with a/c compressor). when i look at where this air pump should be, it is not there. i desperately need to know what size belt i need to use. my power steering pump is still there and everything. please help me with this. thanks in advance