Engine dies when it gets wet (sometimes...)

6 Months ago, when entering a carwash, the engine on my 1999 Honda Accord stopped immediately as the underbody spray hit the car. I rolled it back, tried a few times, and it started and ran as though nothing happened.
Earlier this week, during a rain storm, I drove through a puddle and again, the engine immediately stopped and I coasted to a stop. Both times electrical components in the car continued to work (wipers, lights, windows), but I tried to jump it just in case to no avail.
I had it towed to a repair shop where they said that all the harnesses were wet, so they dried it out and was able to get it to run again. But they couldn’t tell where the water was coming from. There is also an issue with the center panel fuse (radio and power outlet); it shorts out whenever replaced with a new fuse (not sure if this is related to the main issue…).

I called a Honda Dealership repair center to see if this was something they had heard of before with this model/year, and it was new to them. They also said not to bring it to them since their diagnostics wouldn’t discover anything if it was running.

The car is running fine now, but I’m always going to expect it to stop unexpectedly.

Any ideas?

Most vehicles will do the same thing if the ignition components get wet especially the coils. A friend of mine has a fleet of late '90’s to early 2000 Chevy Astros that will stall if they hit a rain puddle too hard. Once they dry out they run great again.

Change out the wires and the distributor. Put dielectric grease on the boots of the plug wires before installing them.