🚗 Classic Fault — Mercedes-Benz (1968–1976)
W114 instrument voltage stabiliser failure
💰 Estimated Repair Cost
$15 – $50 GBP
Parts and labour estimate
🔧 Tools Required
Multimeter, dash removal
📋 Overview
The bi-metallic voltage stabiliser behind the instrument cluster fails and causes fuel and temperature gauges to read incorrectly.
🩺 Symptoms
- Fuel gauge fluctuates wildly
- temperature gauge reads incorrectly
- both gauges affected simultaneously
🔍 Possible Causes
- Failed voltage stabiliser
- broken instrument ground
- sender unit failure (only one gauge affected)
🛠️ Diagnosis Steps
If both gauges are erratic simultaneously, stabiliser is suspect. Test voltage at gauge — should be stable 10V
✅ Most Confirmed Fix
Voltage stabiliser replacement
88% of users confirm this fix worked (21 reports)
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