Test Alternator Charging Current - AR15.40-P-5011GQ

Engine 157, 276, 278 in model 292 

Engine 157, 276, 278, 651 in model 166 

Engine 276 in model 251 

Connection diagram, shown on model 166.0 

Courtesy of MERCEDES-BENZ USA

	Check
1	Detach cover for upper belt drive to the front and remove upwards	Engine 651 in model 166
2	Check poly-V belt tension
3	Check poly-V belt for wear	Engine 157, 276, 278 in model 292 Engine 157, 276, 278, 651 in model 166 Engine 276 in model 251
		Engine 157, 276, 278 in model 292 Engine 157, 276, 278, 651 in model 166 (except 166.063)	AP13.22-P-1352CW
		Engine 276 in model 251	AP13.22-P-1352RTC
4	Check electrical lines to on-board electrical system battery (G1), alternator (G2), starter (M1) and on the ground point for the on-board electrical system battery at the front right (W10) in the engine compartment for form seating and check for a perfect condition
5.1	Remove corresponding underfloor paneling	Engine 157, 276, 278 in model 292
		Engine 157, 276, 278, 651 in model 166	AR61.30-P-1001GQ
5.2	Remove front and center engine compartment paneling	Engine 276 in model 251	AR61.20-P-1105RT
6	Check ground strap between engine and body for tight seating and proper condition and replace if necessary
7	Connect up load tester (079) with current clamp (065) according to connecting diagram
	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
8	Start engine
9	Check charging current at fast rpms, whereby the on-board electrical system battery (G1) is loaded with the load tester (079)		AR15.40-P-9301-02GQ
		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.
		Engine 157 in model 166, 292 Engine 276 in model 166, 292 Engine 278 in model 166, 292 Engine 651 in model 166 Charging current for alternator	*BE15.40-P-1001-01L
		Engine 276 in model 251 Charging current for alternator	*BE15.40-P-1001-01I
10	Check alternator (G2) diodes	If the charging current is below the specified value.
		If diodes are defective ↓ Replace alternator (G2)	AR15.40-P-9301-02GQ
		Engine 651 in model 166	AR15.40-P-5032GR
		Engine 276 in model 166, 251, 292	AR15.40-P-5032GQ
		Engine 157, 278 in model 166 Engine 157, 278 in model 292	AR15.40-P-5032MLJ
11	Turn off engine
12	Clamp off load tester (079) with current clamp (065)