Chevy S-10
Nissan Frontier
Rodeo Events

How do you replace the alternator on a 1999 Chevy S10 ZR2 4.3L V6?



User Avatar
Wiki User

Since no one responded, I did this one on my own. 1. Disconnect both battery terminals ( safety first ) 2. Use a 3/8 ratchet to disengage the serpentine belt tensioner and put some slack in the serpentine belt to remove from the alternator. Sounds worse than it is, but may require two people if you can't use two hands at once. 3. Once the belt is off, you can now start to remove the alternator. 4. There are three bolts - two on the front and one behind near the top of the unit. Note: there is also a bolt directly behind the alternator that holds what appears to be a ground wire from the battery. 5. Once the bolts are removed, I used a screwdriver to gently pry the alternator loose - no problems. 6. Turning the alternator so I can see the back of it, remove the electrical connector. 7. Using an open faced wrench and ratchet wrench, loosen the bolt holding the ground wire. This will look like a spark plug cover on the back, but it's just a bolt. REMOVAL DONE Now reverse the steps with the new unit and reassemble in that order. Starting the vehicle it ran a little sluggis as it took time for everything to reset, but after about a 20-30 minute drive, all was well and guage is happily back to 14 now. I ordered the part online for about 90 dollars with a core charge return of $16.00 Total time took me about an hour - ( I took my time ) If I had to do it again, it would take about 1/2 hour.