🚗 Classic Fault — Mercedes-Benz W115 (1968–1976)
Alternator brushes worn — battery not charging
💰 Estimated Repair Cost
$15 – $50 USD
Parts and labour estimate
🔧 Tools Required
Multimeter, basic tools
📋 Overview
Alternator brushes wear down causing the battery charge light to flicker initially, then the battery goes flat. Often diagnosed as a complete alternator failure unnecessarily.
🩺 Symptoms
- Battery charge warning light on
- battery going flat
- charge light flickers at idle
🔍 Possible Causes
- Worn alternator brushes
- broken brush spring
- corroded slip rings
🛠️ Diagnosis Steps
Measure battery voltage with engine running at 2000 RPM — should be 13.8-14.4V.
✅ Most Confirmed Fix
Replace alternator brushes. Clean slip rings with fine sandpaper.
82% of users confirm this fix worked (25 reports)
🏷️ Parts Needed
Alternator brush and slip ring kit
🔗 Other Mercedes-Benz W115 Faults
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