Alan, Try calling Rick, the owner of "RV Refrigeration" located in Tucson AZ. They rebuild cooling units as well as repair of all brands of RV frig's. They are well aware of those contact problems your having. Great people willing to help.
I don't have a Norcold but Rick did tell me to pass on a tip to others that they must inspect the contacts and clean if necessary before they cause serious problems. I have posted this before.
Should anyone need a rebuilt cooling unit replaced or shipped, I highly recommend and endorse RV Refrigeration. From experience this year with a failure and seeing how they rebuild them, I would now prefer one of their Ribuilts over a new OEM colling unit.
RV Refrigeration, 800-950-4874, Rick. See their Web page .
http://www.rvrefrig.com/
Good luck,
Pat