Generator Noise Diagnosis. Cadillac DeVille 2003

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 2003 🢒 DeVille 🢒 Engine 🢒 Engine Electrical 🢒 Generator Noise Diagnosis

Diagnostic Aids

Noise from a generator may be due to electrical or mechanical noise. Electrical noise (magnetic whine) usually varies with the electrical load placed on the generator and is a normal operating characteristic of all generators. When diagnosing a noisy generator, it is important to remember that loose or misaligned components around the generator may transmit the noise into the passenger compartment and that replacing the generator may not solve the problem.

Step	Action	Value(s)	Yes	No
Schematic Reference: Starting and Charging Schematics
1	Did you perform the Diagnostic System check for Engine Electrical?	--	Go to Step 2	Go to Diagnostic System Check - Engine Electrical
2	Turn OFF all electrical loads. Start the engine. Install a scan tool. With a scan tool, view the Ignition 1 Signal parameter in the PCM data list. Does the scan tool indicate the voltage is within the specified value?	11.0-15.5 V	Go to Step 3	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
3	Turn OFF the ignition. Connect a charging system tester to the battery (follow the manufactures instructions). Operate the engine at 2,500 RPM. Adjust the carbon pile as necessary in order to obtain the maximum current output. Is the generator output within 10 A of the specified value or above?	98 A	Go to Step 9	Go to Step 4
4	Maintain the engine speed at 2,500 RPM and continue to operate the generator at the load test value. Measure the voltage drop between the generator output terminal and the battery positive terminal. Is the voltage above the specified value?	0.5 V	Go to Step 6	Go to Step 5
5	Maintain the engine speed at 2,500 RPM and continue to operate the generator at the load test value. Measure the voltage drop between the battery negative terminal and the generator metal housing. Is the voltage above the specified value?	0.5 V	Go to Step 7	Go to Step 8
6	Test the battery positive voltage circuit between the generator output terminal and the battery positive terminal for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	--	Go to Step 9	Go to Step 7
7	Repair the high resistance in the ground circuit between the generator housing and the battery negative terminal. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?	--	Go to Step 9	--
8	Replace the generator. Refer to Generator Replacement . Did you complete the repair?	--	Go to Step 9	--
9	Operate the system in order to verify the repair. Did you correct the condition?	--	System OK	Go to Step 3