MGB Roadster

1962-1980 / Roadster / United Kingdom

All MGB Roadster problems All workshop issues

Common Electrical

Earth (Ground) Connection Corrosion

Symptoms

Intermittent electrical failures, dim lights on one side, instruments reading incorrectly, indicators flashing at wrong speed.

Cause

The MGB relies on the body as the earth return path. Corrosion at earth strap connections -- engine to body, body to frame, battery earth -- creates resistance in the circuit. This is the single most common cause of electrical problems on the MGB.

Fix

Clean every earth connection to bright metal, apply dielectric grease, and retighten.

Add supplementary earth straps if necessary.

Cost: $0--30.

Cost mentioned in fix

Cost: $0

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Other known issues

Common Electrical

Lucas Alternator and Charging Failures

Dim lights, slow cranking, dead battery, charging light on the dashboard.

Common Electrical

Ignition Component Failure

Sudden engine death, misfiring, no-start condition.

Minor Body and Structure

Sill Corrosion (Inner and Outer)

The outer sill skin bubbles, softens, and eventually perforates. In advanced cases, the outer sill crumbles when prodded. The inner sill -- the structural member -- rots from inside the box section and loses its load-bearing capacity.

Critical Body and Structure

Floor Pan Corrosion

Soft or perforated floor pans, particularly in the footwells and under the seats. Wet carpet is a telltale sign. In severe cases, you can see the road through the floor.

Minor Body and Structure

A-Post Corrosion

Rust at the base of the windscreen pillars where they meet the scuttle panel. This area can be invisible until advanced.

Minor Body and Structure

Door Skin Corrosion

Rust along the bottom edge of each door, working upward from the inside.

View all 18 MGB Roadster problems