Distribution
Review how the Rule Rule-A-Matic 35A Float Switch connects, how it operates and which installation requirements apply to this model.
Open this example as a new project. Use your own parts and cable lengths to make the plan yours.
Two-wire inline control requires a selected compatible pump and its fuse; a generic standalone load circuit would misrepresent it.
Two-wire inline control requires a selected compatible pump and its fuse; a generic standalone load circuit would misrepresent it.
Wiring diagram
Open this example in Crimp to use your own parts and cable lengths. Review the assumptions and installation notes as you adapt the circuit.
Installation notes
Guidance for this model, with sources linked beside the relevant advice.
Verified against the manufacturer's documentation (rev. 950-0520A Rev C, November 2021), checked 2026-10-01. Manufacturer documentation →
Rule-A-Matic 35A is a removable-base float switch. The manual rates it for 14 A at 12 V or 7 A at 24 V. This record models the 12 V installation with a 14 A switched-path limit; it does not support changing the circuit to 24 V while retaining 14 A. Select a pump whose operating and starting demands are compatible with the switch. The number 35A identifies the product, not its current capacity.
Connect the protected positive supply to one switch lead and the other lead to pump positive, following the pump and control-panel diagrams. Pump negative returns directly to the negative bus. There is no negative lead on this two-wire float. Use the pump manufacturer’s specified fuse; the switch contact rating is not a recommendation to fit a 14 A fuse. Its factory leads are 16 AWG and approximately 28 inches long; extension cable must satisfy the whole pump circuit’s current and voltage drop.
Install the base at or above the pump base on a suitable mounting pad. Do not drive mounting screws through the hull. Keep the float free of debris and obstructions through its full travel, and respect the illustrated tilt limits: 30 degrees in the long direction and 5 degrees across it. The nominal on level is 2 inches and off level 3/4 inch. Put splices above the highest expected bilge water and seal them against corrosion.
With the circuit isolated, check free float travel and secure wiring. Restore power and lift the float to confirm that the pump starts, then lower it and confirm stopping. Repeat with water so the installation proves drainage and the intended levels, not only switch movement. Inspect periodically for fouling and sticky travel. The drawing’s high-water and low-water states only open or close the positive path; they do not simulate actual water level or certify automatic bilge protection.
Rule installation manual, 950-0520A Rev C, November 2021; printed pp. 7–11 model identity and ratings, pp. 12–15 installation and wiring. The original PDF is retained in the marine source ledger. The drawing represents the identified electrical interfaces; it does not simulate the equipment’s mechanical performance, radio signals or fluid system. Unpublished connector ampacity and startup current remain unspecified.
Build it out
Add 35A to your diagram, then connect your batteries, chargers and loads. Crimp calculates cable sizes and checks the connections as you draw.
Every cable you draw there is sized against ABYC E-11, from the same tables as the reference on this page.
Technical reference
Check the model, ratings and connection points against your own unit before choosing installation hardware.
Check stud sizes, fuse type, run length and how warm the space gets against the gear you actually have before you order.
Catalog connection points, current direction and planning limits. Check the manufacturer's pinout and connector ratings before installation.
Supply +
in
positive · input
Pump +
out
positive · output
Method & provenance
Manufacturer specifications describe the equipment. Crimp calculates cable results from the circuit and assumptions you enter.
From the maker
Manufacturer, model, ratings and which terminal does what come from the catalog. A newer revision, or the nameplate on the unit in your hand, can say something different — when it does, the nameplate wins.
ABYC E-11
Sized against ABYC E-11. Boats built to UK or EU rules answer to ISO 13297 — check these figures against it before you build. The run length and the current above are what drive the result. Crimp doesn't know how warm your space gets; draw the cable inside an engine-bay zone on the canvas and it sizes for the heat.
Next step
Open this example as a new project. Add your equipment and cable lengths, then review the sizing and checks for your setup.