The indicators are flashing at a rate of 120 times per minute. What is the cause of this phenomenon?

[allcarsnew007]

The F31 vehicle I own has recently exhibited a malfunction involving the brake lights. Upon investigation, it was discovered that the earth pin on the rear driver's side is burnt out and completely missing. To address this issue, a temporary solution was implemented by splicing a piece of wire to the earth cable that connects to the pin holder. Additionally, an attempt was made to ground the bulb holder using a spade, but the rapid flashing of the lights persisted. As a result, the spade was removed and a bare wire was connected to the bulb holder, which was then covered with glue and electrical tape.

[James_Cam00]

Driven by curiosity, I disassembled the defective FRM II device and saw the presence of localised corrosion on the printed circuit board (PCB). In an attempt to rectify the issue, I want to undertake a cleaning procedure to eliminate the corrosion. Drawing on my prior experience of successfully resolving a similar problem in my Volkswagen Crafter's electronic control unit (ECU) via the use of a toothbrush and isopropyl alcohol, I will employ the same method in this instance.