Emergency starter switch for Yanmar 4JH2-TE

[walterc]

A mechanic recommend I wire an emergency engine starter switch directly to the starter solenoid. It would be a push button switch mounted about 4 ft. from the solenoid.

Does anyone know the gauge wire that would be needed, and what the switch should be rated at?

Thanks,

Walter Conner
s/v Flying Cloud

[Blue Stocking]

I use the Cole Hersee push button model. About 3/4" dia, and 3" long. 10G. will handle it easily.

[four winds]

I don't have the numbers you seek.

But generally speaking you could take a look at the wire on the solenoid (the smaller one) that engages the starter via the factory switch for an insight.

Then stop by NAPA or another auto parts store and look for a universal push button starter switch. If they have more than one choose the heavy duty one.

It's just the current required to operate the solenoid so not that much, at least compared to the current for the motor itself.

[four winds]

Originally Posted by Blue Stocking

I use the Cole Hersee push button model. About 3/4" dia, and 3" long. 10G. will handle it easily.

Yes, I was going to guess 10 and suggest 8 for a margin of safety, but decided not to be specific.

[jstevens]

I think your mechanic was not really suggesting an emergency switch, but a mechanic's switch that would allow him to start the engine without having someone in the cockpit at the engine controls. Good idea regardless.

John

[btrayfors]

Invaluable, actually, if you sail singlehanded as I often do.

Blue Stocking has it right: Cole-Hersee push button switch and AWG10 wire. I've had one on my boat for almost 20 years and found it to be indispensable.

Bill

[MaritimeBristol]

Interesting. I had to use the screwdriver across the solenoid contacts trick a couple of times last summer. Having a dedicated back up switch sounds like the way to go. Wasn't too keen on attempting a hand crank on the Yanmar but should probably try it at some point.

[SteveInMD]

Wouldn't it be the same size as the wire going to the key switch?

[Stu Jackson]

Originally Posted by SteveInMD

Wouldn't it be the same size as the wire going to the key switch?

The distances are likely to be very different, so not necessarily.

[SteveInMD]

Originally Posted by Stu Jackson

The distances are likely to be very different, so not necessarily.

Right - so it could be smaller. You are not trying to carry starter motor current, just key switch current.

[HopCar]

I have one with leads that have alligator clips on the ends. I think mine are 16 ga. No more than 14 ga. It doesn't take much current to activate the solenoid. I just keep it in my tool box. The leads don't need to be very long. I clip one lead to the hot terminal on the solenoid. The other lead goes to the small positive terminal. Push the button completes the circuit and activates the solenoid. It comes in handy if I want to turn the engine over while I'm next to it. It's an old mechanics trick.

[pcmm]

I just use screwdriver to jump the solenoid terminals when needed!

[Capt Gary]

HopCar has the right idea. I do the same with the alligator clips. The old Yanmars are notorious for bad wiring between the key in the cockpit and the starter. Having a backup has come in handy a couple of times for me.

[HopCar]

Here you go. $15 at Home Depot.
GearWrench Remote Control Starter Switch-124DD - The Home Depot

[a64pilot]

Originally Posted by SteveInMD

Right - so it could be smaller. You are not trying to carry starter motor current, just key switch current.

No, an "emergency" starter switch bypasses the solenoid, just like the screwdriver trick does, so it is carrying a lot of current.
The solenoid is most often the failure point, not the key switch, so if your not bypassing the solenoid, then your emergency switch will only work if the starter switch fails, but not if the solenoid does.

I'll stick with a screwdriver when and if I ever need it, and replace what breaks that causes me to go to the screwdriver, cause I have yet to do that on a boat, ever. I've done it on farm equipment once in a blue moon and my Sons 1987 Suzuki Samurai, but nothing else in 40 years.