MODS : Was going to post this in 'Technical' but as it's just a comment to help others I'm putting it in here. If it's in the wrong please move or close it.

My '53 boot hatch had been intermittent opening for a while and finally stopped about a week ago. Having looked at the many posts on here I decided to take the push button and motor out and do some checking with a multi-meter to see which was faulty.
With the switch out I just noticed that on the 3-pin connector (not the loom) the pin that would be connected to earth was covered in blue-coloured copper contamination. I cleaned this up using a flat-blade screwdriver gently and this solved the problem. Hope this is of help to someone