How do you replace the alternator on a Chevy S-10 pickup?
These directions are for the 2.2l 4-cylinder engine. Disconnect
the battery cables from the battery (8mm), and remove the battery
from the vehicle. When you go to the parts store to get your new
(or remanufactured) alternator, take it with you and have them test
/ charge the battery. You will kill your new alternator if you use
it to charge up a low-charged battery.
Remove the 2 plastic push-tabs (flathead screwdriver or some
needle-nose pliers) on the intake tube that attach it to the fan
shroud. Disconnect the intake tube from the airbox and throttle
body (flathead screwdriver). Remove air tube, taking care to ensure
the A/C lines aren't damaged in the process. Remove the top half of
the fan shroud by removing the 7 screws (3 on the upper-radiator
support, 2 down on each side of the fan, all 10mm). Place a 3/8"
ratchet on the tensioner and turn it counter-clockwise (like you
were loosening a bolt). Pull belt off the alternator pulley, and
watch your hands next to the sharp fan blades as you let the
tensioner return to it's resting position.
There are three bolts that hold the alternator in place. First
remove the 15mm bolt that is on the top of the alternator on the
back side (a stubby rachet wrench is perfect for this as it's a
tight spot). Then remove the power wire that goes to the battery
(covered by rubber insulation; 13mm; if it's too tight or you can't
reach it, wait until later). Then loosen the 13mm bolts found at
the bottom on the back side and the bottom-right on the front side.
Remove the rear 13mm bolt, then support the alternator with your
left hand as you remove the front 13mm bolt with your right hand.
It should fall right into your hand, but if it does not gently
rotate it back and forth while trying to pull it towards the
Remove the electrical connector on the back of the alternator
(there's a little clip that holds it in place; just lift it up and
pull the connector out). The alternator will now rest on the
battery so you can remove the power wire if you were unsuccessful
earlier (again, 13mm).
Installation is the reverse of removal.