sounds like your gauge is broken or there is a short in wiring
Check fusable links
Never disconnect a battery while an engine is running!
There is a wire from the alternator to the starter motor. On the starter motor end, there is a fusible link that sometimes melts. With the engine off, check the battery volts and check the volts on the big red alternator wire. If they are not the same voltage, the link is open. If the link is open, the battery will not charge
Battery light usually means alternator not charging. Most common solutions would be be a bad alternator, bad connection, or loose alternator belt. If the battery and alt test ok than check the connections to the alternator and battery. You may also have a battery drain (something that is staying on and killing the battery)
You probably have a bad alternator or bad wiring.
if it is like a ranger there is a plug on the driver's side wheel well that looks connected but squeeze it together it should work
It might have something to do with the alternator.......... or maybe there is a short in the wiring
Your battery isn't being charged or accepting a charge
sounds like to me the voltage regulator is bad.if it is mounted on the fire wall replace it could possible short all of that againIn that year & size engine, the VR is probably integral to the alternator, that is, the alternator & VR is usually changed as an assembly.The battery ground cable may be bad. The cable runs along the frame on thepassenger side. My '90 Ranger 4.0 had the same problem, found the cable was corroded/frayed at a clamp in the fender area. Replaced the cable, no more battery drain. FYI, NAPA was the only parts store that carried the correct cable at the time I replaced it.
You run the risk of damaging the alternator.
Loose cables, bad battery, alternator or starter.
The Ford Ranger alternator bolt torque specification is dependent upon the year of the Ford Ranger. In general, the alternator bolt torque specification is 45 pounds.