Can anyone tell me why my v6 3.oL 5spd Mighty Max p.up would be stalling when I attempt to accelerate from a standstill when the steering is fully turned right or left? As well, I have noticed that the headlights are dim and the heater fan motor is lacking speed when the truck is idling, but when I give it a shot of gas the lights brighten and the fan motor speeds up. This seems to go away as the truck gets warmed up.

I have checked and replaced the clamp around the + battery terminal, and checked the - ground connection of the battery. I also checked the level on the power steering fluid. My next guess would be an alternator problem perhaps? How would I check this, or would there be something else causing this?

Check your engine ground wire. If the motor is not grounded just using turn signals will stall you.

I would expect the brushes in the alternator are worn out.
Also check that the wire to the switch on the steering pump is there, but that is a secondary issue.

check alt voltage output at idle and with the lights/blower on.

should be at least 13.5v loaded down.

for the power steering issue check the pressure switch (i think its on the pump. every other mitsu ive worked on is) its supposed to bump the idle up slightly when the wheel is turned