On Thu, 31 Dec 2020 18:32:12 +0000, Adrian Caspersz wrote:

The 10A relay contacts are probably now some tarnished metal as the
current is too low to keep them 'wet'[*], and probably a better choice
will be one specified to switch signals rather than power.

Or pop the cover off and pull a strip of paper between the contacts
while they are manually pressed together.

--
Cheers
Dave.