+1 to GW's advice. I have a litre bottle of ACF50, so filled the cap and poured it into both parts of the connectors, replugged then smeared ACF50 Corrosion Block on the back of the connectors/wires before placing inside inner tubes. Took a while but hopefully it'll outlast the bike now.
No idea why a motorcycle wouldn't have waterproof connectors in the first place or at least have them located in a less vulnerable area? Big design flaw on Suzuki's part.