Scott, WD40 does not conduct! Water might cause a short, where copper contacts are used, by electrolytic effect (meaning an element of voltage must be present to create an electrolytic path across the contacts; this would occur via hysteresis where the voltage passes through the starter solenoid [magnetic switch] and will present itself on the starter wire at the button contact -- the ignition would have to be ON to cause this electrolysis). WD40 will purge any water immediately, but not necessarily the electrolytic path. However, I reckon you may have a shorted starter wire inside the throttle cave.I made the mistake of spraying some WD-40 in there once which leaked into the starter button area, therefor completing the circuit and forcing the starter to kickover everytime the ingnition was turned on. Oops.
Experience 1, WD40 saves the day: Back in '75 I had a MkII Mini 1275 Cooper S; ploughed it too fast through a rather large puddle that was deeper than I anticipated and literally flooded the distributor, thus stopping the car in the middle of 6" of muddy water. Lifted the bonnet (OK, hood), shin-deep in chilly water, removed the distributor-cap & leads, sprayed the inside of the cap with WD40 and shook it out. Stuck the whole lot back together, squelched back inside, flicked the key and it fired up. Drove out of the bloody puddle/small lake v-e-r-y s-l-o-w-l-y! That's at least 10,000 volts of HT, so it definitely won't 'track' or short out at 12 volts.
Experience 2, copper contacts, water & volts: Take one Sunseeker Predator 58 with poorly-fitted windlass footswitches on the foredeck; add heavy rainfall during the night and mix well with rainwater seepage into one of the footswitches. The recipe of water & copper contacts caused the contacts to 'make' sufficiently to pull the solenoid and pay out the anchor chain, all by itself; the anchor was secured with its safety clevis pin in place so the chain bunched and jammed the gipsy, the gipsy clutch was wound tight so the windlass motor burnt out.
