The check engine lights on 1996 and newer can only be turned off using a code reader designed for OBD II. I do know that AutoZone will read the codes for free if there is one nearby you. If you are in a state that requires emission testing, clearing the code will keep them from passing it until the computer has cycled enough times to read all the sensors enough times. Also, you probably won't be able to detect most things that cause the light to come on, the sensors in these systems can measure very small changes. Repairing the problem is the best way to turn it off.
The battery has nothing whatsoever to do with the bonnet on a Ranger. There is either a hood release inside the truck under the dash drivers side or the hood release in located outside under the front edge of the hood.
Do any of your courtesy lights work , or your headlights ? If not , it sounds like a poor cable connection to your battery or a dead battery
ABSOLUTELY ! disconnect your negative battery cable , then your positive battery cable , and wait at least 2 minutes for the back up power supply to drain
battery cable connection , dead battery
The battery is underneath the driver's seat.
Loose or corroded battery terminals? Bad starter solenoid? Bad starter?
www.motorcraft.com ( one of Fords websites ) shows Motorcraft BXT56 ( top of the line ) or BXL56A , as the Motorcraft battery choices for the 1984 Ford Ranger
Your battery isn't being charged or accepting a charge
Right in front of the battery, between the battery and radiator.
Motorcraft BXT - 59 ( is Fords " top of the line " battery for a 2002 Ford Ranger )
fordparts.com shows the battery group size as being ( 56 )
The battery warning light illuminates when the battery isn't being charged , get it checked out to find the problem and then repair.