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Part# 07-03563
MFR Model# STS-S24


FAA-PMA APPROVED for Certified Aircraft

Intermittent Duty, (Starter Solenoid). Available in 12V or 24V. Activation: +V to S-Terminal.
(Frame is grounded by mounting).


  • Silver contacts provide 300A in-rush capability. Much higher than the original units.
  • Strong spring and high-current coil for quick contact opening - minimizing arcing
  • Single coil terminal (other end connected to case).


  • FAA-PMA Certified - stop using automotive parts and operating in the 'gray area' (aka. non-conformance) of the FAR's!
  • Lamar High Quality Manufacturing designed to take the beating our piston aircraft dish out
  • Upgraded to perform best with today's lightweight, high torque starters
  • Not automotive store parts with extra mystery terminals
  • Same OE terminal layout used for decades on our aircraft - simple to install
  • Silver contacts (vs. copper) for high-current capability and long-life
  • All-metal case construction
  • Current draw: 2.9 amps.
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It works great

Jama H Verified Purchase


March 25, 2022

Gene C Verified Purchase


June 16, 2021

Great product. Quick and easy install with very good instructions.

Kirkpatrick D
May 6, 2021

Perfect - as needed and on time.

December 15, 2020

Installed in a PA-32 (Cherokee 6). Fit and functioned perfectly.

John H
December 11, 2020

I believe this is a better quality starter than the one I had in my Beechcraft A35. The only issue I ran into is that the mounting holes had to be reamed because my firewall mounting is narrower than the smallest spacing on the Solenoid. I needed to gain about 1/3 inch in order to mount it. Also even though it is intuitive the instruction does not mention that the ground wire should mount to a mounting screw.

John F
October 6, 2020

Installed in a 1966 PA28-140. Fit perfectly without any modifications and works as advertised

Rick S
September 22, 2020

I needed a relay. I bought this one. It works.

Dennis M
August 24, 2020

Shipped fast on time— fits— works — hope it lasts as long as original Bakelite solenoid— should order diode at same time : )

August 13, 2020

great service

Andrew G
July 27, 2020


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: How much does this Sky-Tec Starter solenoid weigh?

Without packaging, solenoid by itself weighs approx 1 lbs.The solenoid weighs 1.2 lbs with packaging.

Q: I am replacing the original starter on my 1967 Cessna 150G with a Skytec kit Kcst2. Which Skytec solenoid should I order?

For a 12V system see part number 07-03562. For a 24V system see part number 07-03563.

Q: Why is this Sky-Tec starter solenoid intermittent?

Starter solenoids / relays are intermittent, and Master solenoids / relays are continuous.

Q: What size are the terminal studs on STS-S12 starter solenoid?

5/16" on the main studs and there is a small stud that is 3/16".

Q: What is the distance between mounting holes?

2-1/4" hole center to hole center.

Q: Does this solenoid have an internal diode? The solenoid that I am replacing looks like it has a diode in the wire that goes from the S terminal to the mounting bolt.

There is no internal diode. These do not need a diode to function properly, but we always recommend hooking the new contactor up the exact way the old one was connected.

Q: What is the mount bolt torque?

Per the manufacturer: We do not have a torque spec for the mounting bolts. You would just tighten the bolts down to fully secure the unit.

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