The door lock, on your 1999 Mercury Cougar, can be replaced by removing the inside door panel. The locking mechanism is easily visible and can be changed.
To disable a factory installed alarm on a 1999 Mercury Cougar, place the key in the ignition. Turn the key only halfway and let it sit in that position for 10 minutes before starting the vehicle.
Check the fuses and the relay that controls the door locks. A power loss is the most likely cause of the problem.
If the bearings in the alternator get bad enough it can lock up.
If the sliding door on the 1999 Mercury Villager will not stay open, check for something that is not allowing the latching mechanism to lock into place. Make sure that the door is all the way back so that it can lock in.
It sounds like the security alarm is stuck. While this is happening take the key out of the ignition and shut the drivers door, then lock and unlock it with the key. If the problem stops even for a minute then the alarm is the problem.
What? Barn door lock on a Yukon????
If you remove door panel you should have access to unit
Thedoor latch/lock assemblies are not repairable. Replace it with a new one.
You can get a diagram for the door lock assembly in the Haynes 99 Mercury Mountaineer Repair Manual. The book is available at most auto parts and major book stores.
The fuel pump on a mercury cougar is in the fuel tank. You are going to have to remove the fuel tank, take the lock ring off of the tank, and then pull the pump assembly out.
in 1999
If the electric door lock is frozen on a 1999 Suburban, a hair dryer can be used to warm the area of the door where the lock mechanism is. If the key entry is also frozen, there is a lock de-icer pen that can be used to spray away frost in the keyhole.