Changed battery. key fob & overhead controls will not open any doors.

Does the key fob have a good battery in it ?

Locate your second key fob -
Try using that key fob -

if it does not work, and you can verify the Batteries in both Fob's are good - it could be a couple different things.

1. your security system control box may be 'bad'.
2. their is a 'ring' around the key area that are notorious for going bad and preventing the car from starting - however...they don't prevent the key fob from remotely opening the door locks.
3. The power feeding the security system is interrupted (blown fuse, etc) -

I would do the following:

1. Check the second fob and see if it works - If it does you have a bad #1 key fob (or battery).
2. Check ALL of the fuses (in the dashboard Drivers side access panel) AND under hood - Check even those not labeled security - as there are often fuses that feed more than one item, but are only labeled for one item.
3. Try going inside the car, shut all the doors, and lock/unlock the car five or six times using the interior control - I believe this is supposed to reset the unit.
I could be wrong - you can look this up. It might be that you have to do this with the key fob but I can't recall.

Give those things a shot. Also, make 100% sure all of the doors, hood, trunk, etc are fully closed.

I'd just about bet you have a bad key fob - finding #2 is the key here.

Beyond that - it's probably a trip to the junkyard for a new security module and matching set of key fobs - But long before getting involved in that - I'd bet you have a bad key fob or blown fuse -

Security Modules and key fob's are not universally replaceable, are extremely difficult to work with (for those without VIDA [Volvo Diagnostic software] and programming capabilities) and have to be programmed to work with the control unit to which assigned.

Need make model and year. Sometime the fuses are located under the hood or up under the drivers side dashboard.

Did you try programming the key fob? Your owners manual has this info. I don't know if programming will help or not? Just a thought.
fleet.ford.com should have your owners manual, if you don't have one,you can read it for free.
Also try owner.ford.com
has owners manual you can look at for free.

Better answer, check your fuses. Not sure about your specific vehicle but most fuse box's are either under the dash or open drivers door and check for a panel on side of dashboard (where dash meets door)

Sounds like a bad fuse block

if key not opening than you have an internal problem which you need to open door and remove door panel go around and enter vehicle from passenger side and open door behind door panel are rods with clips that operate release their are also spring on latch itself but usually the clip breaks or becomes disconnected most auto stores carry a replacement clip

Sounds like a fuse issue. check your panel for popped accessory fuse.

the overhead light issue may be the door close switch

check for loose ground at drivers side switch