This 2002 Chevrolet Suburban came in with the battery light on and the system voltage at 12 volts. In talking with the customer, I found out that the battery light had been coming on and going off for a bout a week. Yesterday the battery went dead while driving. I was pretty sure just from this explanation that the alternator brushes were worn out. I performed a couple of routine checks and decided to pull the alternator for inspection. The first step would be to disconnect the battery negative cable and from there the intake tube needs to be removed. There is a hose clamp that has to be loosened at the MAF sensor.
There is also a hose clamp at the throttle body that needs to be loosened.
With both ends of the tube assembly loose from the MAF sensor and the throttle body, there is one push pin fastener that has to be removed from the underside of the assembly.
Now using a wrench, ratchet and socket or the tool I am using the tensioner assembly needs to be rotated to relieve the tension on the belt. then the belt can be removed from the idler pulley and subsequently the alternator pulley.
Disconnect the harness from the voltage regulator by lifting the latch and pulling on the connector body.
Loosen the 10 mm nut and remove the cable from the alternator.
Loosen and remove the two mounting bolts. You will need to use a pry bar to rotate the alternator up and out of the mounting bracket.
Although I had not heard any bearing noises while the engine was running I always spin the alternator pulley and feel for any problems before replacing the brushes.
Before installing the repaired or replacement alternator, the slide bushings need to be squeezed back as shown below. They just need to move a 1/16″ to allow the alternator to drop back in the bracket easily.
All back together and charging like it should, as indicated by the voltmeter reading.