Typically the THERMO-VALVE fails.


1268300484 W126 Windshield Heater (THERMO-VALVE)
http://www.peachparts.com/shopforum/showthread.php?t=209303



Have a great day.

__________________
ASE Master Mechanic

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

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