How to Replace the Alternator in a Pontiac Bonneville

The alternator in a Pontiac Bonneville operates various accessories in the vehicle by transmitting an electrical current while the engine is running. The alternator assembly frequently includes a voltage regulator which maintains a constant voltage level. If your headlights become dimmer while driving or your battery keeps running down, you may need to replace the alternator.

Instructions

1

Determine which alternator your Pontiac Bonneville will need. You'll want to be sure the new alternator is compatible with your Bonneville's engine. The Pontiac Bonneville has a long production history of unrelated vehicles. The last generation was made from 2000 to 2005 and was available with a 3.8 L L36, 3.8 L L67 and 4.6 L LD8 engine.

2

Look at earlier generations of the Pontiac Bonneville. Models made from 1977 to 1981 have 231 ci, 265 ci, 301 ci, 350 ci or 400 ci engines. Options for 1982 to 1986 include a 231 ci, 305 ci, 2.8 L, 4.3 L or 350 ci diesel engine and 1987 to 1999 models have a 3.8 L engine.

3

Disconnect the negative battery cable with a socket wrench and the supercharger belt, if present. Remove the accessory drive belt and fuel injector sight shield, if needed, to access the alternator.

4

Remove the nut and bolt on the brace for the alternator and the retaining nut for the wiring harness with a socket wrench. This will allow you to disconnect the electrical wiring from the alternator. Take the two mounting bolts off of the alternator with a socket wrench and remove the alternator assembly.

5

Install the new alternator assembly and tighten the mounting bolts to 37 foot pounds with a torque wrench. Connect the wiring to the alternator and torque its retaining nut to 111 inch pounds. Torque the nut for the alternator brace to 37 foot pounds and the bolt to 22 foot pounds.

6

Attach the fuel injector sight shield and the accessory drive belt. Install the supercharger belt, if present, and the negative battery cable with a socket wrench.