There are two parts, right? The fob (which has a battery), and the radio receiver that the fobs talk to. If the fob light activates but neither fob works, I would be looking at the receiver. It may have lost power (fuse), or its antenna may be blocked or disconnected, or maybe it just quit. A glitch could have interrupted its programming too, so re-programming to the fobs might get it going again.
You should have a small manual for the locks in the set that [hopefully] came with the coach, but if not you can probably get one online. Fleetwood used to utilize locking systems from
HDC Poplocks, but I don't know if that's what yours has or not. A call to
Fleetwood Customer Service should help identify what you have and where to get help.