What jafo says is correct, there is something that might make it a bit easier this is something we do as part of a service in the garage, Get some silicone spray and spray the whole engine every conector and electrical part you can find! its great stuff.
When the bloke used to come and try to sell it to us in bulk, as a test he would get a tank of water and a live mains light bulb, he sprayed it with this spray and grabed it with his hand and dunked it in the tank, sure enough the bulb worked, he didnt die and nothing shorted out. of course hes not alowed to do it now but.. the point is it really does a good job of keeping water out!!!