1999 ranger battery will not charge replaced battery & alternator still no charge

There is a 175 amp fuse that is blown. Follow the wire from the alternator to the fuse panel. This is where the fuse is , replace it.

Can't charge a dead battery--- that is due to be replaced

What was tested & how on alternator

Voltage,Current Output ?

Have to have voltage to alternator regulator from where
ever it comes from

This is easy to test but you need a multimeter. Connect the multimeter to the battery and run the engine at a fast idle (say 2000 rpm). You should get a voltage reading anywhere from 14 to 15 volts if the battery is fully charged and the alternator is working. If the reading is around 12 volts, then the alternator is not working.

If the ignition switch is effected by the loose
key cylinder ,it may play a role

You need to check out the switch
and look at a wiring diagram to see
what role the ign sw plays, with grounding
the alternator regulator,if it does

Put an AMP Meter in either battery cable
to check for excessive drain

I would replace the alternator. The test might of proved it was ok but that just checks to make sure its putting out the amperage its rated at. Sounds like its shorted internally and putting out full amps all the time.

well...whenever the battery light comes on in a vehicle its almost always a charging problem,i would suggest replacing the alternator and charging the battery before starting it,alternators were meant to keep a battery charged NOT charge a battery, hope this helps

sounds like alternator charging output is zero, should run off of alternator output after a jump start, preform a complete charging system check , Battery , Alternator, Cables...Replace as needed...

is voltage at battery when engine running and headlights on around 13.5-14volts?
if so its not the alternator
do a current draw test with amp gauge in system with everything off 0.02-0.05amp good any more than an amp will drain battery over night something staying powered up or a short can cause this

If there is power to the big wire that is bolted on to the back of the alternator and no power out of the small wires that plug in to the alternator then it is possible you need to replace your alternator. start the vehicle and check to see if there is 14 volts at the battery while the vehicle is running if there is then the alternator is good if not replace your alternator and charge your battery with a charger to make sure you have a proper charge on the battery.

yes, remove it just with common hand tools, take it to autozone and they can test it,
get yourself a haynes manual #36071