Battery light came on, I replaced the battery and alternator and the light is still on and the volt meter is showing about 12v. Battery cables are tight. What's wrong. Thanks

 

Might try checking electrical harness at alternator for damage to wiring/connectors.

 

What year is the truck? The older rangers used an external voltage reg your's might be bad.

 

According to his profile , it's a 93 , so it's internal.
To the OP , check ALL the grounds from the battery.
Bat to frame,bat to engine,bat to body.

 

did you load test the alternator and battery. just cause they are new doesnt mean they are good

 

Load tested everything, Truck seems too drive great right now, Were wouldI find the volage regulator too inspect it.

 

may be a bad starter solenoid.....i went through the same thing on my 95 but my batt light never came on the volt guage would just drop..so i replaced that and had to redo the batt wires at batt connectors and no its fine.

 

Ok so I replaced the starter soleniod, battery, and alternator and I still dont have any voltage.

 

check grounds...my charging light came on in my old car...it was just a loose ground thats prolly all yours is