Test coolant gage - AR20.30-P-4460A

ENGINE 111 in MODELS 170, 202, 208, 210 

ENGINE 112 in MODELS 129, 202, 208, 209, 210 

ENGINE 113 in MODELS 129, 171, 202, 203, 208, 209, 210 

ENGINE 156 in MODEL 209 

Fig 1: Identifying Ring Magnet And Coolant Level Indicator Switch

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

	Removing
1	Remove coolant level indicator switch (S41)	The coolant level indicator switch (S41) is not directly enveloped directly with coolant and can be removed from the expansion reservoir or radiator without draining the coolant.
		Model 209 with engine 156	AR20.30-P-4392PI
		Except model 209 with engine 156
	Checking
2	Connect multimeter (DMM-5) at coolant level indicator switch (S41)	Electrical connection set	Fig 2
		Multimeter	*WH58.30-Z-1001-09A
3	Test switching point of 'maximum' coolant level	Use float with ring magnet from expansion reservoir of models 129, 140, 202, 203, 208, 209, 210. Check without using the ring magnet (1)! If the resistance indicated by the multimeter (DMM-5) = ∞ (infinite) ↓ Replace coolant level indicator switch (S41).
4	Test switching point of 'minimum' coolant level	Guide the ring magnet (1) along the coolant level indicator switch (S41) to do this until the contact switches in the coolant level indicator switch (S41). Specified resistance ≈ 5 Ω! If the contact is not switched or if the resistance indicated is too high: ↓ Replace coolant level indicator switch (S41).
	Install
5	Fit coolant level indicator switch (S41)	Model 209 with engine 156 Except model 209 with engine 156	AR20.30-P-4392PI

Fig 2: Identifying Electrical Connection Kit (220 589 00 99 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.