Mercedes-Benz ML320. Service manual - part 394

Test values for generator charge indicator lamp 

CHECKING REGULATION VOLTAGE OF ALTERNATOR - AR15.40-P-5010GH 

ENGINES 111.977, 112.942/970, 113.942/965/981, 612.963, 628.963 in MODEL 163  

to vertical position

 As of A145273, X708319. AR88.40-P-1000GI 

 

Testing 

 

 

2

Check electrical line 
terminal 30 to the following 
items for firm seat and 
flawless condition



Battery (G1) (+)  



Generator (G2)(B+)  

 

3

Check electric cable for 
circuit 31 at the following 
positions for correct seat 
and condition



Battery (G1) (-)  



Right major assemblies 
compartment ground, 
Common ground 
(W16/4)  



Engine ground 
strap/body  

 

4

Inspect tension of poly V-
belt

 

 

5

Inspect operation of charge 
indicator in instrument 
cluster

 

*BE54.30-P-1001-01A

6

Install in the reverse order

 

 

Number

Designation

Model 129, 163, 168, 
170, 202, 203, 208, 210

BE54.30-P-1001-01A

Position of ignition / glow 
start switch

Charge indicator lamp 

Off

0/1

Charge indicator lamp On 2

 

2001 Mercedes-Benz ML320 

1998-2005 ENGINE Electrical System - Engine - 163 Chassis

  

me 

 

Fig. 30: Identifying Connection Diagram - Checking For Alternator Regulation Voltage 

 

Checking 

 

 

 

Risk of explosion caused 
by oxyhydrogen gas. Risk 
of poisoning and caustic 
burns caused by 
swallowing battery acid. 
Risk of injury caused by 
burns to skin and eyes 
from battery acid or when 
handling damaged lead-
acid batteries

No fire, sparks, open flames 
or smoking. Wear acid-
resistant gloves, clothing and 
safety glasses. Only pour 
battery acid into suitable and 
appropriately marked 
containers.

AS54.10-Z-0001-01A 

 

Notes on battery

 

AH54.10-P-0001-01A 

1

Check condition of 
battery (G1)

 

AR54.10-P-1129Z 

2

Check whether 
preconditions for 
alternator testing have 
been fulfilled

 

AR15.40-P-5009GH

3

Attach volt ampere tester 
(079) according to 
connection plan

 Volt ampere tester with 

load resistance

*WH58.30-Z-1002-09A

 Volt ampere tester ETT 

011.00

*WH58.30-Z-1003-09A

 

Risk of accident caused  Secure vehicle to prevent it  AS00.00-Z-0005-01A 

 

2001 Mercedes-Benz ML320 

1998-2005 ENGINE Electrical System - Engine - 163 Chassis

  

me 

 

by vehicle starting off by 
itself when engine is 
running. Risk of injury 
caused by contusions and 
burns during starting 
procedure or when 
working near the running 
engine

from moving by itself. 
Wear closed and snug-fitting 
work clothes. 
Do not grasp hot or rotating 
parts.

4

Start engine

5

Check function of charge 
indicator lamp when 
engine is idling and with 
increasing engine speed 
(up to 3000 rpm)

 Charge indicator lamp 

must extinguish.

 

6

Load battery (G1) using a 
permanent consumer and 
check regulation voltage 
of alternator (G2)

Engines 111, 112, 113

*BE15.40-P-1001-02A

Engines 612, 628

*BE15.40-P-1001-02C

 Volt ampere tester with 

load resistance

*WH58.30-Z-1002-09A

 Volt ampere tester ETT 

011.00

*WH58.30-Z-1003-09A

Regulation voltage > 15.0 

V: ? 



Replace regulator  

 
Engine 628

 

Engines 111, 112, 113 



Replace alternator 
(G2)  

AR15.40-P-5760GH

Engine 612 

Regulation voltage < 13.0 

V: ? 



Check electrical 
connections for 
charging system for 
transition resistances; 
repair if necessary.  

 
Electrical connections OK: ?

AR15.40-P-5032GI



Check alternator (G2) 
diodes  

AR15.40-P-9301-02EA

 

2001 Mercedes-Benz ML320 

1998-2005 ENGINE Electrical System - Engine - 163 Chassis

  

me 

 

Check values for regulator 

Check values for regulator 

Commercially available tools 

CHECKING CHARGING CURRENT OF ALTERNATOR - AR15.40-P-5011GH

Engine tester with 
oscilloscope 
If diodes are faulty: ? 



Replace alternator 
(G2)  

*WH58.30-Z-1046-13A

Engine 111, 112, 113

AR15.40-P-5032GH

Engine 612

AR15.40-P-5032GI

Engine 628

AR15.40-P-5032IA

7

Turn off engine

 

 

8

Disconnect volt ampere 
tester (079)

 Volt ampere tester with 

load resistance

*WH58.30-Z-1002-09A

 Volt ampere tester ETT 

011.00

*WH58.30-Z-1003-09A

Number

Designation

Engines 103,104,111, 
112,113,119, 120, 
137, 155, 166, 275

BE15.40-P-1001-
02A

Regulating voltage 
(at battery)

Loading: only on 
permanent consumer

V 13 to 15

Engine speed

rpm 3000

measured after

min approx.2

Number

Designation

Engines 
601,602,603, 604, 
605, 606, 
611,613,628, 646, 
647, 668

Engine 612 
except 612.966

BE15.40-P-
1001-02C

Regulating 
voltage (at 
battery)

Loading: only on 
permanent 
consumer

V 13 to 15

13 to 15

Engine speed

rpm 3000

3000

measured after

min approx.2

approx.2

Number

Designation

WH58.30-Z-1002-09A

Volt-amp(s) tester with load resistance (no longer 
available)

WH58.30-Z-1003-09A

Volt ampere tester

WH58.30-Z-1046-13A

Engine tester with oscilloscope

 

2001 Mercedes-Benz ML320 

1998-2005 ENGINE Electrical System - Engine - 163 Chassis

  

me