Service manual

6-20 Engine Electrical Engine
2006 LSSV Service Manual Supplement
24V Generator Noise Diagnosis (cont’d)
Step Action Yes No
9
1. Replace the drive belt tensioner. Refer to Drive Belt
Tensioner Replacement in Engine Mechanical – 6.6L
in 2006 C/K Truck Service Manual.
2. Start the engine.
Has the noise decreased or stopped?
System OK Go to Step 11
10
Compare the vehicle with a known good vehicle.
Do both vehicles make the same noise? System OK Go to Step 11
11
Important: If no definite generator problems were found, be
sure that all other possible sources of objectionable noise are
eliminated before replacing the generator. Replacing the
generator may not change the noise level if the noise is a
normal characteristic of the generator or the generator
mounting.
Replace the generator. Refer to 24V Generator Replacement.
Has the noise decreased or stopped? Go to Step 12 Go to Step 2
12
Operate the system in order to verify the repair.
Did you correct the condition? System OK Go to Step 2
24V Generator Inoperative
24V Generator Inoperative
Step Action Value(s) Yes No
1
Did you perform the Diagnostic System Check –
Vehicle?
___
Go to Step 2
Go to
Diagnostic
System Check
– Vehicle in
Vehicle DTC
Information in
2006 C/K
Truck Service
Manual
2
Using a DMM, measure the voltage across the 24V
battery terminals.
Is the voltage between the specified voltage?
18.0-28.5V
Go to Step 3
Go to Battery
Inspection
Test (Optima)
3
1. Start the engine.
2. Using a DMM, measure the voltage between
the generator terminal B and ground.
Is the voltage greater than the specified voltage?
7V
Go to Step 4 Go to Step 6
4
Using a DMM, measure the voltage from the BATT
terminal and ground.
Is the voltage greater than the specified voltage?
7V
Go to Step 5 Go to Step 7
5
Connect a test lamp between ground terminal of the
generator and battery negative.
Does the test lamp illuminate?
___
Go to Step 8 Go to Step 10