it looks like a control valve for the heater system as it has two coolant hoses and a pair of wires that plug into it. quite a complex looking thing as most mercedes parts are. its located just behind the r.h. headlamp. my wires have been cut off and i don't know what purpose this serves, and what am i not seeing with these wires cut ? ? ? i could take a pix of it for clairity. help !
davidh

its a 83, 300d. why do i forget to do this all the time ?

AUX water pump, for the heater system.


Vehicle 1983 Mercedes Benz 300D Turbo
Part: Auxiliary Water Pump
Note:
This unit has 12" lead wire. Bosch 0.130.002.070
W0133-1608481
Auxiliary Water Pump Bosch IN STOCK


Have a great day.

__________________
ASE Master Mechanic
https://whunter.carrd.co/

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
2003 Volvo V70

https://www.boldegoist.com/

how is the heater able to function with this pump not operating? it gets nice and warm in the car so far. . .

__________________
david h
83 300D Alabama Beauty (Son's)
83 300D West Coast Rust Free that been abused

Because the engine water pump does most of the work.

Aux pump only works during low speed operation.

Are you sure it's not the receiver/dryer?

__________________
Bob
'82 300D Petrol B-G Metallic