One will be the EEC relay (that powers the engine management system), the other will be the fuel pump relay. Factory relays are usually black for the EEc relay, and green for the fuel pump relay, but there's no telling what you'll get if they've been replaced. If you look at a wiring diagram to see what color wires go to which relay should allow you to identify which relay is which (the ones in Chiltons are usually adequate for this, and can be obtained for free in the vehicle repair guides at autozone's website if you don't have the print manual).
'87 Bronco II XLT 4x4 & '92 Explorer XLT 4x4 & '98 Chev Suburban K1500 SLT 4x4
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. Ford® is a registered trademark of the Ford Motor Company.