On the Merkurs this module is in a dumb spot where it can get wet from a pillar leak. So many people find corrosion once you pop it open. Bin it then.

Open it an and find nothing? Well Ford didn't exactly have military spec solderers on staff. Go get a really cheap soldering iron (30w) and some good solder and reflow the board. Worked a charm in my car.

I doubt you have corrosion since on RHD euro cars it's in a far better spot, but reflowing it might be a good option for you.