I guess the traditional answer would be an insulating (usually petroleum) grease/jelly (Vaseline). Not sure about its compatibility with modern plastics etc though.

Possibly a better approach is to look at why water is getting into or pooling in the system in the first place - modern design normally do take moisture into account, so maybe it's more down to a missing/damaged/displaced O-ring or a blocked drain hole or something of that nature.

   - Andy.

Hi Andy, thanks for the reply.  This is a known fault on the Ford Transit Customs. I'm pretty sure washer fluid is able to find its way down to the back of the connector that plugs into the wiper motor control module in the photograph. The fluid is effectively funneled down through the non waterproof connector ending up at the module connecting pins where it stays and corrodes. The reason for my post is that we have worked on desert ralley (Dakar) motorbikes in the past which have also suffered from extreme conditions and were wondering if there was something other than the usual treatments like petroleum jelly or grease that would inhibit corrosion. 

Hi Andy, thanks for the reply.  This is a known fault on the Ford Transit Customs. I'm pretty sure washer fluid is able to find its way down to the back of the connector that plugs into the wiper motor control module in the photograph. The fluid is effectively funneled down through the non waterproof connector ending up at the module connecting pins where it stays and corrodes. The reason for my post is that we have worked on desert ralley (Dakar) motorbikes in the past which have also suffered from extreme conditions and were wondering if there was something other than the usual treatments like petroleum jelly or grease that would inhibit corrosion.