You can't fix it till you know what's wrong with it.
To fix the windshield wipers on a 1993 Mercury Villager, first check the fuse and replace it if it's blown. If the fuse is intact, inspect the wiper motor and linkage for any signs of damage or corrosion. You may need to remove the wiper arms and the cowl cover to access these parts. If the motor is faulty, replace it; otherwise, ensure all connections are secure and lubricate any moving parts.
There is no way to change gear ratios.
In my experience , my villager would not shift from park to anything. Found a T20 or T25 torx screw under dash by steering column to be really loose on shifter linkage. Works great now!
Replace the instrument cluster.
It is not repairable, you should replace the instrument cluster.
These parts are only fixed by replacement.
You can't "clear" it unless you fix the problem that is causing the light to be on in the first place. That's the way all airbag systems work.
There is no fixing a broken motor mount. Replace them with a new ones.
remove the battery terminals for a minimum of 10 minutes.
yes
You would fix it by replacing the instrument cluster. The speedometer itself may not be faulty, it is more likely to be a problem with the speed sensor.