JRreadyST6318-401 Deutsch DT 4 Pin Connector Kit - 8 Sets Gray Waterproof Automotive Connector with Size 16 Solid Contacts 14-20AWG

I bought to install connectors on my Harley truck and they made the install easy. They come with water tight plugs and the metal connectors are tight

I really like these for automotive projects that require water-resistant electrical connections. These are very similar to European OEM style connectors and much better than the older style, weather-pack connectors that are more difficult to crimp. There are enough plug ends in the kit to make 8 connections. If you don't need 4-pin connections on all of them you can use the sealing plugs and go down to three or two-pin connections.