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Part# 11-03161
MFR Model# 70 111226 5B1
VoltageCoil TerminationManufacturer PNPart No.
12VCoil Common to NO70 111226 5B111-03161


(Battery Solenoid) - Applicable to all homebuilts. Continuous duty. 12V and 24V.
California Prop 65 Warning Symbol

WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov.


  • High current capacity control
  • Isolated or grounded coils
  • Enclosed in dust-resistant case
  • Longer steel encasement permits lower heat rise and more sensitive operation on Type 71


  • Dielectric Strength: 500 Volts
  • Temperature Range: -40F/-40C to 122F/50C
  • Mechanical Life (no load): 250,000 operations
  • Electrical Life (rated load): 100,000 operations
  • Mounting Position: Recommended mounting with cap down
  • Vibration: 5 gs vertical and horizontal planes
  • Weight (approximate): Type 7014.0 oz.
  • Duty Cycle: Continuous
  • Hardware Torque Specification: Contact Terminal: 45-55 inch-lbs, Coil Terminal: 12-18 inch-lbs.
  • Mounting Bracket: 100 inch-lbs. max (a backup wrench must be used to hold the bottom nut stationary during installation)


  • Frequently Purchased With
  • Customers Also Viewed


Received promply as ordered

William C Verified Purchase


September 26, 2023

Dont trust your life to a cheap chi-com solenoid. Good stuff

Brett B Verified Purchase


February 21, 2023

Fast shopping and great service

Ray O Verified Purchase


December 15, 2022

She was great whom ever I had talked to.

Gary Verified Purchase


November 1, 2022

Same, as the one that failed . To early to rate.

Richard L Verified Purchase


September 21, 2022

I bought this at Oshkosh 2022. Installed it and flew home. Worked as advertised. The service at Oshkosh was remarkable. Thank you!

Charles R Verified Purchase


August 12, 2022

Everything is perfect about the order. I got the right part and it arrived faster than the estimate. I suppose a schematic included would have reduced head scratching a little, but overall no problems. It is perfect for the intended use. Oh yes, is there an internal diode to protect the operating circuit from the reverse EMF when the relay is shut off.

Louis W Verified Purchase


February 4, 2022

Works great you NEED ink in your printer!!

Louie L
April 12, 2021

Worked on first try, so far so good. At this price, I should have installed it at the same time as the starter relay, since theyre wired together. 90% of the labor is getting at the the starter relay.

Duffy F
April 1, 2021

Showed up with the nuts and washers needed to make the connections and it works perfectly. The insulated portion for mounting allowed for 1/4 carriage bolts to be used. Came in handy getting it mounted, only needing a single wrench to tighten it down. Battery side clearly marked.

Bob H
May 30, 2019


Please note, Aircraft Spruce's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Aircraft Spruce assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.

Q: For this part, is it correct ground the insulated case and use +12 to engage the relay. ( connected to the control terminal)?

Per the manufacturer, the answer is no. The terminal going to the coil is the negative side and should go to the master switch, and the positive side of the coil is common to the power terminal.

Q: What is the peak amperage rating, and the constant amperage rating?

Regarding part number 11-03161, the maximum inrush rating is 150 amps and the continuous duty rating is 80 amps.

Q: Does the coil of the relay have a diode to prevent any excess voltage spikes (as recommended by Dynon)?

Per the manufacturer, no it does not. Regarding part numbers 11-03161 / 11-05799.

Q: Is there a drawing available for these master relays? Specifically one that shows the terminals. Thanks.

We have added the drawing to the "Documents" tab of this web page. Please review it there.

Q: What is the current draw of the coil in amps?

The 70-111226-5B1 is a 12V continuous duty solenoid, so therefore the coil is rated at approximately 9 watts. Since P= IV. Or, 9=I (12). So for a 12 volt system, the current is 0.75 amps

Q: Can this relay be used in series with the starter circuit with a series Starter relay?

No, because the starter circuit requires high amperage we do not recommend using this relay.

Q: Does this relay can replace Cessna part 0850469-1?

No, these master relays are intended for use on experimental aircraft only.

Q: There are 2 images shown, one with 2 relay terminals and the other with 1. Which one do you receive when you order the 12 volt relay?

The single terminal version is the 12 volt. If you click for the full size image, you will see each image is watermarked with the sku for that product.

Q: Is there a recommended mounting orientation for the solenoid?

"Recommended mounting with cap down" per TDS.

Q: If its recommended to mount with the cap down why is the sticker (with writing) put on upside down? Once mounted the words will be upside down on the mounted solenoid.

This is shown cap down on our website, the writing is not upside down.

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