911 Carrera 2 Targa F6-3600cc 3.6L SOHC (1992)
Battery: All Technical Service Bulletins
Battery - Discharged Unit Diagnosis
Group
2
Number
9402
Model
4 & 6 Cyl.
Part Identifier
27
March 29, 1994
Subject:
Diagnosing Discharged Battery
ATTENTION: Service Manager / Service Technician
Models Affected:
968 from Model Year 1992-on
911 Carrera 2/4 1989-1994 and 911 Turbo 1991-on
Concern:
Discharged battery diagnosis through the central electric board and current draw checking.
The following information has been produced in connection with Technical Bulletin Group 2, 9204, dated September 29, 1992. In an effort to avoid
repeating covered subject material, only the following topics are discussed:
1.
Current draw checking. (Updated information from Technical Bulletin Group 2, 9204.)
2.
Diagnosing defective relays. (New information.)
3.
Checking current draw and electronic components through the central electronic board. (New information.)
4.
Battery charge lamp (excitation voltage, charging voltage) and alternator/regulator checking. (New information.)
IMPORTANT:
Before checking current draw, determine the age of the battery, acid level and density.
Diagnosis Program:
The following procedures should be used to diagnose the aforementioned points.
Step 1: Current draw checked at rest is accomplished by using an amp meter connected in series between battery minus cable and the battery minus pole.
Select the four amp scale or greater. Switch to the 40mA range without interrupting the circuit.
-
Procedure: Any aftermarket accessory (telephone, stereo, CB radio, etc.) must first be disconnected completely (remove fuses, etc.).
-
Check the on-off switching points for the door switches, glove compartment or engine lid.
-
Set the trunk switch to the "off" position on 6 cylinder vehicles and the engine lid switch to the off position on 4 cylinder vehicles.
-
Record customers radio station presets.
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Close all doors and lids and be certain all consumers are switched off.
-
Disconnect battery minus cable.
-
Connect amp meter as in Step 1.
6 Cylinder - Maximum allowable current draw for 911 C2/4 1989-1993 = 26mA
-
If the battery current draw is higher than 26mA, the cause must be determined.
