I have been in need of a new 4 wire connector, for my cruise control. I wound up using the molex connectors which come with PWM computer fans.
I sealed the ends where the wires enter with clear rtv. Been that way for 10+ years now, no issues.
I'd likely use Amazing Goop instead of clear rtv if I were to do it again today.
Nice solution to your needs.
I very much enjoy having multiple ammeters. My Sears clampmeter is suprisingly accurate at low currents. I bust it out to check the other ammeters or wattmeters incase they drift.
Most recently I used it on a '30 watt' woodburner which was running through a router speed controller. 0.22 amps was too hot, but 0.18 amps was perfect for what I was doing. On the 360 degree dial there was about a 3 degree difference from 0.22 to 0.18 so dialing in the heat via amperage was much easier and more precise.
Could not have done it withuot the clampmeter.
My point is, a ac/dc clampmeter is extremely useful, and in the states can be as low as 32$.