schematics and diagrams: How to replace alternator on GMC Sonoma?

The procedure to replace Alternator is as follows :----

Disconnect the negative battery cable.

Remove the air inlet duct assembly, if necessary.

Carefully relieve the serpentine drive belt tension, then remove the belt from the alternator pulley. Do not allow the tensioner to snap back into position once the belt is off the pulley.

Remove the nut retaining the radiator hose brace to the back on the alternator.

If equipped, unfasten the retainers, then remove the brace from the engine and/or the alternator.

Disconnect the battery terminal boot wiring from the back of the alternator, then unplug the regulator wiring connector.

Support the alternator and remove the mounting bolts (usually 2) from either side of the alternator, then remove the alternator from the vehicle.

To install:

Position the alternator in the vehicle and loosely install using the mounting bolts.

If equipped, loosely install the brace to the engine and/or alternator.

Tighten the left or front alternator retaining bolts to 36 ft. lbs. (50 Nm), the right or rear alternator bolt to 18 ft. lbs. (25 Nm), the brace bolt to 18 ft. lbs. (25 Nm) and/or the brace nut to 22 ft. lbs. (30 Nm), as applicable.

Connect and secure the alternator wiring.

Carefully relieve the serpentine drive belt tension and position the belt over the alternator pulley, then slowly release the tensioner into position.

If equipped, install the air inlet duct assembly.

Connect the negative battery cable.

Except 2.2L Engine

See Figures 2 through 7

Fig. Fig. 2: Remove the air inlet duct assembly

Fig. Fig. 3: Unfasten the nut retaining the radiator hose brace to the back on the alternator

Fig. Fig. 4: Remove the electrical wire from the rear of the alternator, ...

Fig. Fig. 5: ... then remove the alternator's mounting bolts ...

Fig. Fig. 6: ... and remove the alternator from the vehicle

Fig. Fig. 7: Alternator mounting-4.3L engine

2.2L Engine

See Figures 8 through 12

Fig. Fig. 8: Alternator mounting-2.2L engine

Disconnect the negative battery cable.

Raise and support the front of the vehicle, then remove the passenger side tire and wheel assembly for access to the rear of the alternator through the wheel well.

Working through the wheel well, unfasten the alternator brace-to-block bolt, then remove the brace-to-intake nut and the brace-to-engine stud nut.

Unplug the alternator wiring connector, then remove the battery terminal nut and wire.

Carefully release the serpentine belt tension and remove the belt from the alternator pulley. Do not allow the tensioner to snap back into position once the belt is off the pulley.

Loosen the alternator retaining bolts, then support the alternator and remove the fasteners. Remove the alternator from the vehicle.

Fig. Fig. 9: The alternator brace-to-block bolts and wires are accessible through the passenger side wheel well

Fig. Fig. 10: After unfastening all the retainers, remove the brace through the opening

Fig. Fig. 11: The top bolt (1) is removed first from the rear of the alternator and is accessible through the wheel well opening, then remove the bottom mounting bolt (2) from the front

Fig. Fig. 12: After the bolts are unfastened, remove the alternator from the engine compartment

To install:

Position the alternator in the vehicle and loosely install the retaining bolts.

On 1994-98 models, tighten the top alternator bolt to 22 ft. lbs. (30 Nm) and the bottom bolt to 32 ft. lbs. (43 Nm).

On 1999-99 models, tighten the rear bolt to 37 ft. lbs. (50 Nm) and the front bolt to 18 ft. lbs. (25 Nm).

On 1994-98 models, install the alternator brace, then tighten the retaining nut(s) and bolts to 22 ft. lbs. (30 Nm).

On 1999-99 models, install the alternator brace, tighten the brace-to-alternator and brace-to-intake retainers to 18 ft. lbs. (25 Nm). Tighten the brace-to-engine stud nut to 37 ft. lbs. (50 Nm).

Install the battery terminal wire and tighten the retaining nut, then engage the alternator wiring connector.

Hold the serpentine drive belt tensioner, back off the belt while slipping the belt over the alternator pulley. Gradually lower the tensioner into contact with the belt, then check for proper alignment and tension.