The speedometer sensor is in the top of your rearend housing.
The most common reason for a speedometer to fail is a broken speedometer cable. Loosen the nuts on each end of the speedometer cable. Remove the speedometer cable retaining clips. Reverse the process to install the new speedometer cable.
Speedometer cable (most common) Speedometer head Gear on transmission end of speedometer cable
check fuses
For a 1994 Ford Aerostar , 3.0 ( and 4.0 ) 3 - 6 2 - 5 1 - 4 front of Ford Aerostar
Yes they are compatible
Yes , I BELIEVE the last year for a speedometer cable on a Ford Explorer was the 1995 model year so the 1991 Ford Ranger would definitely have a speedometer cable
1994 Ford Aerostar Mini Van 1994 Ford Aerostar Mini Van
On a 1994 Ford Aerostar , 3.0 L ( and 4.0 L ) 3 - 6 2 - 5 1 - 4 front of Ford Aerostar
On a 1994 Ford Aerostar , 3.0 liter V6 and 4.0 liter V6 : 3 - 6 2 - 5 1 - 4 front of Ford Aerostar
You can replace the speedometer cable, on your 1988 Ford Ranger, by loosening the cable nut on each end of the cable. The cable will come off and can then be replaced.
As far as I know the 1995 Ford Explorer is the last model year to have a conventional speedometer cable ( so yes )
I believe that 1995 was the last year for a conventional speedometer cable on a Ford Explorer , and then Ford went to an electronic speedometer with a vehicle speed sensor