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Fuel Boost Pump Switch on J35

ABS Full Member
Posts: 16

I am replacing the instrument panel, and with it all of the switches, indicators, and breakers. So far, the mystery is a replacement for the fuel pump switch. Older models, at least the J- and K-35, have a three-position switch, up=ON-Emergency, middle=OFF, down=On-Low. New model Bonanzas have a simplified 2-position on/off fuel pump switch.

The POH never differentiates between the three switch positions in practical use. It is either ON in certain situations (starting/prime or emergencies or problems). Or OFF (not used).

1) Can I replace this switch and resistor with a simple on/off switch as in newer models?

2) If I need a 3-position switch, what switch model/number, and appropriate resistor do I need to buy?

Model: Bonanza J35
Aircraft Serial Number: D5531
Posted 12/4/2019 - 9 months ago
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ABS Full Member
Posts: 1407

You will still need a double pole 3 position switch to provide a high and low voltage to the pump through the resistor. I have attached the wiring print for your aircraft ( last one on the page based on S/N ).

Bob Ripley
ABS Technical Advisor

attachment

CCF_000058.pdf - 305.2 KB

Posted 12/5/2019 - 9 months ago
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ABS Full Member
Posts: 16

Thank you Bob.

Just to be clear, the switch is a 3-position, On–Off–On, DPDT type, such as the AN3027-1, at Aircraft Spruce, correct? Thank you for marking the resistor as well.

Paul

Posted 12/5/2019 - 9 months ago
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ABS Full Member
Posts: 1407

That switch should work fine.

Bob

Posted 12/6/2019 - 9 months ago
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Fuel Boost Pump Switch on J35