🚗 Classic Fault — Mercedes-Benz W115 (1968–1976)
Interior blower motor resistor failure — fan on full only
💰 Estimated Repair Cost
$15 – $50 USD
Parts and labour estimate
🔧 Tools Required
Screwdrivers, multimeter
📋 Overview
The heater blower motor resistor pack fails leaving the fan operating on full speed only. Lower speeds use resistors that burn out over time.
🩺 Symptoms
- Heater fan only works on speed 3
- speeds 1 and 2 do not operate
🔍 Possible Causes
- Failed blower motor resistor pack
- individual resistor wire burnt out
🛠️ Diagnosis Steps
Switch between fan speeds — confirm which speeds are missing. Speed 3 working but others not confirms resistor.
✅ Most Confirmed Fix
Replace resistor pack.
82% of users confirm this fix worked (23 reports)
🏷️ Parts Needed
Heater blower motor resistor pack
🔗 Other Mercedes-Benz W115 Faults
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