Replacing the alternator in your Chevy S10 doesn’t require the attention from a professional at a service shop. Through its 23 years of production, the S10 has retained the easy accessibility to the alternator, making replacement an easy job for the average do-it-yourself mechanic. Follow these steps to replace your Chevy S10’s alternator and you’ll be back on the road before you know it.
1. Disconnect the negative battery line from the terminal. Note: Isolate the wire away from the terminal to ensure there will not be any sort of contact while replacing the alternator.
2. Disengage the serpentine belt from all routed components.
3. Pivot the tensioner pulley counter-clockwise to relieve the tension on the serpentine belt using a properly sized socket wrench.
4. Pull the serpentine belt from the pulley once the tensioner is loose. Note: Do not completely remove the serpentine belt unless you are going to replace it as well.
5. Locate the wiring harness attached to the rear side of the alternator, covered by either a red or black cover that can be disconnected by hand.
6. Disconnect the clamp from the primary wire connection by pressing on the tap with your finger.
7. Remove the primary terminal wire away from the alternator.
8. Remove the secondary terminal wire away from the alternator.
9. Locate the two front alternator mounting bolts and remove them using a properly sized socket wrench. Then remove the rear alternator bracket bolt.
10. Ensure all wires are disconnected from alternator, then lift the alternator using a small pry bar or screw driver.
11. Place the new alternator into the support clamp, and tighten the three mounting bolts to the specified torque.
12. Connect the secondary terminal cable to the new alternator by reapplying the nut. Then pull back the tab for the primary terminal wire and reconnect, pushing the wire in until the tab locks in place.
13. Rotate the serpentine belt tensioner counter-clockwise. Note: If you are changing the serpentine belt as well, refer to the routing guide located near the radiator. The S10’s serpentine belts leave little room for error, so if it does not fit back on the alternator pulley it is more than likely not aligned properly in a different location.
14. Reconnect the negative battery wire to the terminal, and start the S10 to ensure the new alternator was properly installed.
Video Instructions: https://www.youtube.com/watch?v=zbMyuclc2Gc