Alternator is Not Charging

Faulty alternator
Faulty wiring
Blown fuse

1.Using a multimeter verify that the battery has 12v across the battery posts.

A. If there is not 12v, then recharge or replace the battery

2.Verify that there is 12v at the starter buss bar. The starter buss bar is located where the positive battery cable is connected to the starter.

A. If there is not 12v at the starter buss bar verify that the machine has good ground circuit. Replace ground cables as needed.

B. If there is not 12v at the starter buss bar and the machine is well grounded replace the positive battery cable.

3.Verify that there is 12v on the battery post on the alternator.

A. If there is not 12v on the battery post, then a continuity test will need performed between the battery post and the where the wire connects to the starter buss bar.

1. If the continuity test fails, then repair or replace the wire.

4.After verifying that there is 12v at the battery post on the alternator. Locate the cab fuse in the cab fuse panel. The cab fuse panel is located behind the right side console panel. With the key in the run position but with the engine not running. Verify that there is 12v at the cab fuse.

A. If there is not 12v at the cab fuse, then verify the ignition switch is sending 12v to ignition relay on pin 86 and also there is 12v at pin 30 to the relay.

1. If there is not 12V at pin 86, then a continuity test will need performed on the purple wire between pin 86 and the buss bar on the back of the fuse panel.

2. If there is not 12v at pin 30, then a continuity test will need performed on wire 160 between pin 30 and the buss bar at the starter. There is a connection point on the 160 in the cab close to the cab and chassis connections.

5.After verifying that there is 12v at the cab fuse, then verify that there is 12v at the alternator excite wire at the alternator.

A. If there is not 12v at the alternator excite wire, then a continuity test will need performed between the alternator and the cab fuse.

1. If the continuity test fails, then the cab and chassis harnesses will need continuity performed on each harness.

a. If the continuity test fails on the blue wire labeled 15 in cab harness between the cab fuse and pin A1 at the engine bulk 2 connector, then repair or replace the cab harness.

b. If the continuity test fails on the yellow wire labeled 5 in the chassis harness between pin A1 at the engine connector and the alternator, then repair or replace the chassis harness.

2. If there is 12v at the alternator, then alternator will need replaced.