1998 Ford Ranger will have power when I turn the key, sometime no power, why? Then I can wait and some power comes back, changes back and forth.
Defective Ignition Switch
Sometimes pressure from the steering wheel lock will keep you from turning the key switch, try wiggling the steering wheel as you attempt to turn the key.
Is it making any kind of noise or is it not doing anything at all when you turn the key?
that depends on what happens when you try to start it. if when you turn the key nothing happens, then you probably have a loose wire some where so check the battery cables and all the wires on the starter. if when you turn the key it tries to start but won't turn over, then turn the key to the off position, press the gas pedal to the floor and while holding the gas down try again. that's how i had to start my old cavalier and I'm still not sure why that worked.
try to inspect your your lock and tumbler or key ignition switch.
I usually take the key out, turn it, and put it back in ignition to start
Turn the wheel and then try to start it with the key.
If your ignition will not turn, try turning the steering wheel slightly while you turn the key. Sometimes the steering wheel will get locked in place and doing this will allow the ignition to move again.
Turn the key.
turn the key
turn the key!!
Either the starter, starter relay or ignition switch are failing.
Does it turn over? Does it turn over?