Dad has a 2007 Ranger Z21. Very little water will trickle out of livewell when pumps turned on. Noticed the blinking lights on dash for aerator. Didn't find any loose connections. Both pumps spun when I touched wires to batteries. Didn't see any obvious clogs. Seems like our factory pumps lasted for many years, but we've replaced the cartridges several times the last few years. Do i just but 2 new cartridges or is there a short? Many thanks!

I'll be honest, I don't fully understand what you're asking about.
Title says bilge pump
You talk about live well pump
Mention blinking lights for the aerator
Water does move but it is at a trickle speed


But I will say this, I've had pumps before that spun when the power was turned on but didn't move water.
I replaced the pump and it fixed the problem.
Maybe your issue is the same? If not, no big whip. Either keep the pump for a back up or return to get your money back.
But that might be a good place to start.

If the pump vanes get worn and lose clearances, it'll spin fine but hardly force water. If they've pushed water with mud or sand that'll eat em up.

I have had pumps that spun the hubs. Mearing the shaft is loose inside the vanes. Make sure the wires are wired up correctly. If they are wired up backwards the pump will spin but not pump water.

You seem to indicate the pumps are the cartridge style pumps. You say they don't work, and you're not sure why. Why not remove the cartridge from the pump housing to see if you can spot the issue. Example: visual inspection could confirm the vanes are trashed from debris, the vane assemble is sheared from the shaft, etc. Hold the cartridge firmly and turn on the pump. Does it run? Do the vanes turn? Hold a garden hose into the pump housing; have someone turn the water on. Does water flow through the plumbing?

My bad, meant livewell pump

I took them out and gave them an inspection nothing noticed. That's when I also put them on the battery. Probably just buy 2 more and see if that helps.