Doug's problem was corrosion in the quick-connect coupling for his Beta Marine engine wiring harness.  The mechanic he brought to the boat bypassed the coupling wire-by-wire with waterproof hard wired connections.

I try hard to keep my coupling free from corrosion.  I lift it in the air.  I spray it with Corrosion Block.  I use wire ties and tape to try to keep the protective rubber boot watertight.   Nevertheless, thinking about Doug's problem makes me think that having a coupling there in the first place is just asking for trouble.   The only time one needs to disconnect it is if the engine is removed from the boat.  In that case one could simply cut the hard wired connections and replace them later.

Certainly, if one wants top reliability, such as when making ocean crossings, having a coupling in the wiring harness compared to hard wiring sounds like an unnecessary risk.  What do others say?