poulsen11@yahoo.

I have a 2000 Formula 382 with 2 bilge pumps and 2 float switches in the engine compartment, one on either side of the 'tunnel' in the bilge. When one float energizes, both pumps run. There is no weep hole through the 'tunnel' that seperates the 2 sections of the bilge that each pump/float combination serves. I wrote formula and they confirmed that there is no weep hole.

I have lost 2 pumps in the last season due to the bilge running with water in one side and none on the other (one pump running dry). I am using rule 1100 pumps.

I look at the wiring in the dash and i see that the helm switch is a single pole switch that controls both pumps. All wiring looks factory. My brother and i tried for a couple of hours to draw a electrical diagram where each float would control its respective pump independently, but we could not figure out how to do it.

Formula support assures me that the intent from the factory is not to have both pumps energized when just one of the float switches is closed. I'm trying to figure out if there is some way i can resolve this situation without completely re-doing the wiring from helm to engine compartment. HELP!!!!

professor_speed

just wire it so the float switch can break the circuit. (even when energized by the dash switch) The switch on the dash will energize the circuit. So the float switch is wired in series with the pump, port and starboard pump and switch circuits are wired parallel. Sounds like the switches are currently all wired parallel and if that's the case the float switches don't do anything. all the wiring should take place at the pumps and float switches, the dash wiring is fine.

poulsen11@yahoo.

I could do that, but then i would be giving up the ability to manually turn on the bilge pumps at the helm so the switch at the helm would not really do anything. I guess that isnt too big of a deal though. FYI i havent changed any of the factory wiring, this is as it came.

poulsen11@yahoo.

A diagram of the current wiring. As you can see, when the one bilge pump energizes via the float switch, it energizes the 'on' terminal of the SPDT switch and thus energizes the other pump as well. Only way to isolate this (i think) is to have a DPDT switch.

professor_speed

this would make it so that when you flip the switch on the dash the pumps would run only if there is water to pump out. If there is no water they don't pump.(the problem with arrangement is that if float switch fails there is no way to tun on the pump, but you have two so its not likely they will both fail at the same time.) Do you you want to have a manual override and have the pumps to turn automatically with the float switches? In that case you would wire the float switches to complete an always hot circuit. and you would then wire your dash switch also complete the circuit as well, but you would need diodes to isolate each side of the circuit. otherwise one float switch would energize boat pumps.

I have no idea how formula originality wired the boat. is your switch an on-off or is it an on-auto-off switch? I have been assuming that it is a simple on-off.

poulsen11@yahoo.

Thanks for the second reply prof. I just posted a drawing that hopefully will make it more clear. The switch is intended to be an auto-off switch and does work that way, but when one float closes it energizes both pumps which is the behavior that causes one pump to run dry when there is water in the other side. I think having the pumps run dry from time to time is screwing them up as they are not 'run dry' pumps.

This summer i had a situation where one of the pumps went out, i got some water in both sides. One side pumped out and was empty, other side was full because pump was not working. both pumps will run forever in my current configuration instead of just having 1 dead pump, i wind up with 2 and a dead battery to boot!!

professor_speed

Ok you just need isolation diodes for the float switches.

poulsen11@yahoo.

Ha, knew i was missing something. Excellent. Some inline diodes should prevent energizing other pump. Probably easier than finding and installing a matching DPDT switch.

professor_speed

Yup easy fix, minimal wiring

poulsen11@yahoo.

Thank you!!!