A brief update! The replacement PCB didn't cure the fault; with the connectors on the reservoir cap removed, during a further test drive, the light still flashed! So attention moved to the handbrake switch connections & the wiring loom to it. 'wrapping' the wires in a plastic sleeve where they pass over the gearbox & using cable ties to secure as well as checking for possible chaffing of the wires from the bulkhead resulted in no flashing during a further test run. However, after about 15 miles of driving back home there was one brief flash of the light. A further 15-20 miles no further problem. Will monitor closely, & when the opportunity of getting the car on a ramp again arises, have a further inspection.
Thank you for all the suggestions & advice.
