How to Replace the Alternator on a 1979 Mercedes Benz 300SD

1. Pop the hood and disconnect the negative battery cable using a wrench to loosen the nut.
2. Loosen the adjusting bolt until the alternator belt is loose enough to pull off of the alternator pulley. Unplug the voltage regulator harness from the alternator. Disconnect the electrical leads from the alternator using a wrench to remove the nuts.
3. Remove the alternator bolts with a socket and ratchet. Pull the alternator out of the Mercedes.
4. Put the new alternator on the mounting bracket and tighten all but the adjusting bolt with the socket and ratchet. Put the alternator belt on the pulley and tighten the adjusting bolt until the belt is taut. Plug the voltage regulator into the alternator. Connect the electrical wires and tighten the nuts with a wrench. Connect the battery cable and tighten the nut with a wrench.