🚗 Classic Fault — MG GHN/GHD (1962–1980)
MGB overdrive relay failure
💰 Estimated Repair Cost
$10 – $40 GBP
Parts and labour estimate
🔧 Tools Required
Multimeter
📋 Overview
The overdrive relay on Laycock-equipped MGBs fails and prevents overdrive engagement.
🩺 Symptoms
- Overdrive will not engage
- overdrive light on but no effect
- overdrive engages intermittently
🔍 Possible Causes
- Failed overdrive relay
- faulty overdrive switch
- failed solenoid
🛠️ Diagnosis Steps
Test relay by swapping with identical relay. Check solenoid resistance — should be 4-6 ohms.
✅ Most Confirmed Fix
Overdrive relay replacement
88% of users confirm this fix worked (24 reports)
🔗 Other MG GHN/GHD Faults
Own a MG GHN/GHD?
Share your experience with this fault — or report a different issue. Your knowledge helps other classic car owners worldwide.