The 4WD concern may be due to a bad shift motor. I believe the 2000 had a constant drive front differential that only engaged in the transfer case. If the shift motor on the rear of the case does not turn, then you may need to replace the motor. Check for voltage at the motor and post back the results. Also the concern with the turn signals may be due to a bad connection at the rear of the multifunction switch. Remove the steering column shroud and examine the switch (it's the turn signal, wiper, dimmer, hazard switch).