Advance Auto, NAPA, all the different car parts places, and Wal Mart sell electrical cleaner in a spray can. One brand is CRC "QD electronic cleaner" It will cut the corrosion and crap. a hard bristle nylon cleaning brush helps.
mart sell spray cans of electrical parts cleaner. One brand is CRC electronic cleaner.
1998 Pace Arrow 35 ft. F53 Ford V10 2012 Honda Civic toad
32 years mechanic at Delta Air Lines 15 year motorhome service manager. 3 popups....2 travel trailers....5 motorhomes....loved them all.