WD-40 has no place in electrical connectors or components. WD-40 is composed of 80% Stoddard Solvent (that is similar to paraffin), 20% light lubricating oil, and a bit of fragrance. So, I advise against using WD-40 in any part of an electrical system because it leaves an oil residue. Use an electrical contact cleaner instead is to remove any grease and oil that is causing conductivity problems. Sticky relays should just be replaced because in the long run they’ll probably fail when you least want them to.
[Edited on 8-10-2005 by Shazaam!]