Why not change out the pumps for Auto Rules Pumps?
Love mine! No floats to deal with.

You just need a DPDT switch, your back feeding through the opposite pole on the SPDT switch. Diodes just add another point of failure.

Either way, diodes or DPDT switch will probably take about the same time to connect. Although the factory wires all need to be ran to the switch panel to be able to use the DPDT switch, which may or may not be the case. Easy fix!

That diagram is not showing an auto-on- off switch. It shows power in and power out to one pump or the other.
What's your email I'll draw a diagram and send it to you.
[email protected]

If your diagram is correct then you would want to place the diodes on the supply side to the bilge like below:

Its also just as easy to do a DPDT switch and fix it...all depends on how easy it is to get at it all. :)

Yes the bilge switch in a 382 is not a auto-off-on switch. It is a 2 position auto-on switch.

Apparently the NMMA does not allow diodes in the wiring path for bilge pumps. Presumably because their failure could cause a boat to sink. The correct solution is to put in a DPST switch and run a new wire from the helm to the bilge pumps to that i can isolate the energized bilge pump circuits from one another. FYI, the way i am describing the wiring above is the way that Formula wired this boat from the factory, not a great design in my opinion.

However, i will say that Scott at Formula has been very helpful in helping me find the wiring diagrams and such for a 12 year old boat. That is good service IMO so at least they have that going for them.

THanks all for the great posts BTW. This site is AWESOME!!

A DPDT would be the proper fix to isolate the two pump circuits...is this a case where someone at some point replaced the switch with a new one "that looked the same"??? Wouldn't be the first time

sorry - just re-read post 16 regarding the switches direct from Formula...

I am not the greatest when it comes to electrical circuits but, why wouldn't you just mount a second 2 position switch like the first and have one pump wired to each? You probably already thought of this and have a reason.
Alternatively a hole saw will get you water flowing from one side to the other pretty quick :whistle: