another jim warman question:)

hey jim....really appreciated your info on my tranny.....now another " kooky " question....my 94 eb has never ran hotter than normal.....last week here in ohio we had a day of hard rain....i ran it through a deep water puddle.....within a mile or so the temp gauge started climbing...to barley half way or a hair more....never out of the normal heat range...i'm thinking wet belt slippage due to water....but ever since then the gauge will swing between the normal first line to just past half way....then swing back to normal....it has never overheated......even on a extended drive....only going to half or a hair more and back to normal......does this sound like a sensor going bad?....loose wire?.....i've checked fluids and they are all at operating levels, no collapsed hoses, and it throws plenty of heat.....as usual......thanks in advance...scott