Test alternator charging current - AR15.40-P-5011NKB

ENGINE 270 in MODEL 242 

ENGINE 270, 607, 651 in MODEL 117, 246 

ENGINE 270, 607, 651 in MODEL 156 

ENGINE 270, 607, 651 in MODEL 176 

Connection scheme shown on model 246.242 

Fig 1: Testing Alternator Charging Current

Courtesy of MERCEDES-BENZ USA

	Risk of accident  from vehicle starting off by itself when engine running. Risk of injury  (bruises and burns) resulting from working on the engine while it is being started or when it is running.	Secure vehicle to prevent it from starting off by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts.	AS00.00-Z-0005-01A
	Check
1.1	Remove lower engine compartment paneling	ENGINE 270 in MODEL 117, 156, 176, 242, 246
			AR61.20-P-1105NKB
1.2	Remove bottom section of soundproofing	ENGINE 607 in MODEL 156 ENGINE 607, 651 in MODEL 117, 176, 246
			AR94.30-P-5300NKB
2	Check poly-V belt for wear
			AP13.22-P-1352CW
3	Check electrical lines to on-board electrical system battery (G1), alternator (G2), starter (M1) and on the ground point for the battery (W10) in the engine compartment for tight seating and check for a perfect condition
4	Remove air filter housing	ENGINE 607 in MODEL 117, 156, 176, 246	AR09.10-P-1150ORA
		ENGINE 270 in MODEL 117, 156, 176, 242, 246.2	AR09.10-P-1150MT
		ENGINE 651 in MODEL 117, 156, 176, 246	AR09.10-P-1150OLB
5	Check ground strap between engine and body for tight seating and proper condition
6	Connect volt amp(s) tester (079) with current clamp (065) according to connection diagram
7	Start engine
8	Check charging current at high engine rpms; apply load to on-board electrical system battery (G1) for this step using volt-amp(s) tester (079)	Alter load resistance long enough until the maximum charging current is achieved; the charging voltage must not drop below 12.7 V when this is done.
		Charging current for alternator	*BE15.40-P-1001-01L
9	Check alternator (G2) diodes	If charging current is below the specified value:
			AR15.40-P-9301-02W
		If the diodes are defective: ↓ Replace alternator (G2).
		ENGINE 607 in MODEL 117, 156, 176, 246	AR15.40-P-5032ORA
		ENGINE 651 in MODEL 117, 156, 176, 246	AR15.40-P-5032OLB
		ENGINE 270 in MODEL 117, 156, 176, 242, 246	AR15.40-P-5032MT
10	Turn off engine
11	Disconnect volt amp(s) tester (079) with current clamp (065)
12	Install air filter housing	ENGINE 651 in MODEL 117, 156, 176, 246	AR09.10-P-1150OLB
		ENGINE 270 in MODEL 117, 156, 176, 242, 246.2	AR09.10-P-1150MT
		ENGINE 607 in MODEL 117, 156, 176, 246	AR09.10-P-1150ORA
13.1	Install bottom section of soundproofing	ENGINE 607 in MODEL 156 ENGINE 607, 651 in MODEL 117, 176, 246
			AR94.30-P-5300NKB
13.2	Install lower engine compartment paneling	ENGINE 270 in MODEL 117, 156, 176, 242, 246
			AR61.20-P-1105NKB