Trunk and door locks are not interchangeable. The ignition key should work all locks unless the ignition has been changed or the car has been wrecked. Since you have aftermarket keys, my first suspicion would be a miscut key. Ford OEM lock grease is notorious for hardening into industrial strength concrete if the key is not used in the cylinder occasionally, so that is something to look at on the passenger side and trunk. Since the car is a '98, the dealer can't help you with the key. An automotive locksmith can correct the problem either way. The key is a chip key, so this is not a DIY. | 
