It's a certain type (model) that does cycle. Every to minutes it energies for a few seconds. If it feels resistance from water, it keeps going, if not it shuts right back off. It's for applications here there isn't a good place o put a float or for people that don't want to deal with a float.

Edit: Oooops, I posted wrong one in this post.

Sorry about above.

Okay, here: The 'S' models

AUTOMATIC SUMP PUMPS

Rule Pumps 12 Volt DC Automatic Bilge Pumps 500 GPH - 2000 GPH feature computerized operation on the principle of impeller resistance. Float switches are not required. The pump will turn on every 2-1/2 minutes to sense for water. If water is present, the pump will sense resistance
and continue to run until all the water is removed. Thereafter, it will check for water every 2-1/2 minutes.Power use in the checking mode is minimal.
Ships next business day


Rule Pumps 12 Volt DC Automatic Submersible Pump Data
Model GPH Amps @12v Amps @13.6v Fuse Size Height Width Weight (lbs) Hose Diameter
25S 500 1.9 2.5 2.5 4” 2-3/8” 1 3/4”
27S 1100 3.3 5.0 6 4-1/2” 2-3/8” 1 1-1/8”
53S 2000 8.4 12.0 15 7-3/4" 4-3/4” 4 1-1/8”

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

https://www.ebay.com/p/?iid=28241709...pp=true&chn=ps

Just went this route

Got the auto sensing one which does the buzz. Reminds me that the engines should be scooting me across the water rather than sitting on the trailer.

For the OP, if you have a hard time getting to pumps with the engines in, install back-ups now.

Honestly, they all, all suck, just keep an eye on it always and water sensors are even worse.

I bought a couple of the from cpperformance. Price is the same but not real impressed with the quality. I'd like to find something similar go my originals.

Ended up buying 2 new ones with external mounted float switches so they don't cycle ever 2.5 min. Hopefully the make it 19years like the stock ones

Highly doubt it, the vast majority of electronics are crap these days.