I have to spray my switches with the electronic cleaner stuff every 6 months or so. I know they need to come out and be cleaned/replaced, but a shot of that stuff keeps me going. Try simply spraying them in place before you go too deep.
Lewis
84 C10 J code intake.
83 C10 Scottsdale w/veggie conversion.
98 K3500 Silverado CC DRW, marine injectors, 4" exhaust (kitty cat MIA), boost and egt gauges, FSD relocated, #9 resistor thingy, reman Navistar block from Kennedy installed Jan 08, Reese Signature Series Gooseneck hitch.
95 C2500 F code. Rebuilt GEP. Daily driver since Jan 2014.