How to Install an Alternator in a 99 Chevy S-10

The 1999 Chevrolet S-10 was equipped with a 2.2-liter, four-cylinder engine in the base model. A more common engine in the 1999 S-10 was the 4.3-liter V-6 Vortec TBI, which was available as an option for all trim levels that year. The 1999 S-10 was available as a pickup truck or the S-10 Blazer SUV. Replacing the alternator on the 1999 S-10 is a similar process between both the 2.2-liter and the 4.3-liter engines. Size and position of the alternator will vary slightly.

Instructions

1

Raise the hood on the S-10 and set the prop rod. Disconnect the negative battery cable from the battery, using a 3/8-inch drive ratchet and socket. Depress the tensioner with a ratchet and socket, to release the tension on the serpentine belt. The tensioner is the large metal "teardrop" shaped assembly on the front of the engine, with a pulley attached at the outermost point. Remove the serpentine belt from the alternator. It is not necessary to remove the belt from any of the other pulleys.

2

Remove the retainer nut from the back of the alternator, that connects to the radiator hose bracket. Remove the bracket from the alternator. Remove the alternator mounting bolts from the alternator bracket with a ratchet and socket. It may be necessary to remove the entire bracket from the engine to access the electrical connectors on the rear of the alternator, depending on the position of the bracket. Use the ratchet and socket to remove the bracket from the engine if necessary.

3

Disconnect the battery wire from the alternator by removing the tie-down nut with a ratchet and socket. Unplug the negative wire connector from the back of the alternator. Remove the alternator from the S-10 completely.

4

Install the negative connector into the back of the new alternator. Attach the battery cable to the alternator and tighten the tie-down nut snug with the ratchet and socket. Do not over-torque the nut, or you will twist the inner parts of the alternator and ruin the connection. Insert the alternator mounting bracket onto the alternator and snug the mounting bolts at this time, if you removed the bracket from the engine.

5

Install the alternator into the bracket on the engine. Tighten the forward-facing retaining bolts to 36 foot-pounds with a torque wrench and socket. Tighten the rear-facing bolts with a ratchet and socket until they are snug. Turn the ratchet 1/2 turn farther, to approximate the 18 foot-pounds needed for the rear-facing bolts.

6

Depress the tensioner assembly with the ratchet and a socket. Install the serpentine belt onto the alternator pulley. Release the tensioner assembly slowly. Inspect the alignment of the belt throughout the entire belt routing on the engine. Make sure the belt is still centered on each pulley. If you need to adjust the belt, depress the tensioner halfway and make the needed adjustments.

7

Reconnect the negative battery cable, and tighten the cable end to 108 inch-pounds.

8

Turn yourmultimeter on to the "V" or volt setting at the 20-volt indicator. Touch the meter's red probe to the positive battery terminal, and touch the black probe to the negative terminal. The meter should read between 12.00 and 12.75 volts. Start the engine of the S-10, and reconnect the meter probes to the battery. If the battery is not putting out between 13 and 15 volts, then there is more than likely a problem in your alternator wiring.