Dead Crank Switch

RonD2 · Post by **RonD2** » Fri Oct 19, 2018 12:50 pm

10-4, I'm probably just being overly cautious. I bet you weren't starting a 67 year old airplane either!

And there won't be any car shows or parades in my future, unless somebody pays me to do it.

The blood, sweat, and tears are purely for my enjoyment!

Besides, it keeps me out of the saloons.......

RonD2 · Post by **RonD2** » Fri Oct 19, 2018 1:18 pm

"On a summer day around here she only needs about 1/3rd choke to light up."

Forgot to mention that I am using the "Special (Wes) K" gas formula --- 1 gallon of 100LL Avgas mixed with 4 gallons of ethanol-free regular.

Wonder if that has something to do with it? She seems to like it (spark plugs are nice).

Wes (and others!) have taught me here that there's nothing like a well-maintained jeep to ensure easy starts!

Thanks gentlemen!

Post by **wesk** » Fri Oct 19, 2018 9:27 pm

You do the math, I have been flying many aircraft well past 67 years old. 1948 Cessna 170, !950 Cessna 170, 1940 Aeronca Chief, 1952 Cessna L19, 1947 Aeronca Champ, 1953 Piper Tri-pacer, just to list the few built before 1955!

Mike_B · Post by **Mike_B** » Fri Oct 19, 2018 9:37 pm

In addition to the "voltage" switched 3-post solenoids Wes described there are also "ground" switched units, so be careful when shopping to make sure you get the correct one for your application as they look the same.

Mike B

bamaj · Post by **bamaj** » Fri Oct 19, 2018 9:51 pm

About that Ford solenoid. If you are going to run that solenoid be sure to spend the extra and get a made in the USA Ford not an aftermarket solenoid. I'm a Ford nut myself and it's common knowledge that the aftermarket solenoids are junk and are notorious for doing exactly what Wes has described. The best ones can stick but the cheap ones will get you for sure.

RonD2 · Post by **RonD2** » Fri Oct 19, 2018 10:22 pm

10-4 Mike and Jeff........thanks!

I always look for Made in USA parts first. It matters in many ways, at least to me. I suspect the one I have now is off-shore, but works at the moment. Will keep my eyeballs peeled for a NOS.

Problem with this stuff nowadays is you can't tell for sure. Many companies claim Made in USA but it's B.S. when you get the part in your hand and read the "China" stamp. Do they really think they fooled me, or that I'd really buy anything from them ever again? Really gets hard when the part isn't marked with anything.........which makes me automatically suspect off-shore junk.

I think I'll look for a NOS solenoid...old enough to be made here. I'll have to research if the Cole-Hersee solenoids that Wes recommended are still made here. Thats's an old American company, but can't tell anymore.

And for Wes's math lesson, I can't add that high! Good grief!

bamaj · Post by **bamaj** » Fri Oct 19, 2018 11:37 pm

I think the last Ford solenoid I bought was from National Parts Depot for a 65 through 73 Mustang and was about $45.00 but its was almost twice the weight as the ones you get from the box stores. The other thing is if your battery is less than fully charged it has a tendency to cause the contacts to stick.

Post by **wesk** » Sat Oct 20, 2018 12:25 am

In addition to the "voltage" switched 3-post solenoids Wes described there are also "ground" switched units

The "ground switched" units are just the standard externally grounded 4 terminal relay/solenoid. The only difference is how it's wired into the circuit.

With the standard wiring of this relay the starter switch sends 12V to the magnet coil. With the ground switched wiring closing the starter switch actually grounds the magnet coil.

Mike_B · Post by **Mike_B** » Sat Oct 20, 2018 3:12 pm

Wes, your illustrations are correct for the 4-terminal/post solenoids (they can be wired/controlled either way as the coil is isolated from the chassis/housing). But, there are 3-terminal units available with an internal jumper from post #1 to one side of the coil requiring post #3 be switched to ground.

I just wanted to make sure that when someone sees a solenoid at a swap meet they know to be aware, as there are differences even though they might look the same at first glance.

Mike B

Post by **wesk** » Sat Oct 20, 2018 11:16 pm

Mike, Good point. Definitely folks should go by part number not external appearance.

This is the 3 terminal you speak of. The reason one must go by part number?? In the illustration above the 24060 is rated 700 Amps intermittent duty and 24115 is rated at 75 Amps continuous duty. 75 amps would not be a good choice for a starter load.