Stuck Key Switch

[JusDreaming]

One of my key switches is screwed! It is EXTREMELY hard to turn, and sticks in start position. I have tried spraying with electronic spray cleaner, WD-40. When I use WD-40 then exercise the switch it gets better, but if it is not used for a couple of days it is back to square one.
If I remove the switch is there anything I can soak it in to clean it up. A new Perkins switch is $145.00, which with all research I can do is the only correct replacement

[Chief Engineer]

What kind of switch is it?

[GordMay]

You should be able to get an automotive ignition key switch for about $25, at your local auto parts store.

[JusDreaming]

it is an eight terminal switch I can not determine mfg. And Gord I searched all the major switch mfg. web sights and none with the proper terminals. It is a huge switch body on it

[GordMay]

Should only need 3 terminals, including B+, and Pos 2 & Pos 3.
Most regular ignition switches have three positions.
1. Off: key can be removed.
2. Ignition and accessories (guages etc) are activated.
3. Momentary Start position runs the starter motor. This position is spring-loaded to return to position 2 once the engine is running.

[svHyLyte]

FWIW WD40 in not a particularly good lubricant and, once dried, can actually attract dirt and debris making things worse. (In fact, it is very efficient at removing oil and grease and is a recomended cleaner for same.) If the switch needs lubrication, use a light-weight oil such as 3-in-1 or a pressurized misting oil such as one might use on an outboard engine for layup. Turn off all the power to the engine-spray the oil into the key-slot and work the switch back and forth through a few complete cycles until it turns smoothly. There are no electronics in the switch barrel, simply pins and the return spring, so there is nothing for the oil to damage.

I discovered the foregoing when the switch on our Perkins failed to return to the run position after starting the engine, leaving the starter engaged. Before I realized it, the starter had been turned into a generator that completely destroyed our electical system--including the engine shut-off solenoid. I finally got the engine shut off manually but not before our starter was fried and our batteries partially melted--a nearly $2,000 USD repair.

Good Luck...

s/v HyLyte

[GordMay]

Originally Posted by svHyLyte

There are no electronics in the switch barrel, simply pins and the return spring, so there is nothing for the oil to damage.

I discovered the foregoing when the switch on our Perkins failed to return to the run position after starting the engine, leaving the starter engaged. Before I realized it, the starter had been turned into a generator that completely destroyed our electical system--including the engine shut-off solenoid. I finally got the engine shut off manually but not before our starter was fried and our batteries partially melted--a nearly $2,000 USD repair.

Which is one reason to forgo the conventional 2-position spring return switch; and use a simple on-off switch (Ign On) & momentary contact push button (Start).

[David M]

I think that two button ignition system are simpler and more reliable. As a security device for boats, keys are next to worthless and are prone to corrosion. If you are concerned about it, then place a hidden switch somewhere inside the boat that makes it impossible to start the engine.

[Cheechako]

If you want to avoid the $145 switch you will need to track down what the other wires/terminals do. possibly a shut down solenoid? I saved money once and bought the auto switch, however it didnt fit the hole right, always bugged me because it wouldnt stay tight in the panel, it wanted to rotate when turning the key etc. Do you want to risk a $2000 fiasco like mentioned above or just get the right switch and keep it lubricated? I guess it depends on your abilities and tenacity to make it right....

[CharlieJ]

svHyLyte's tale provides a teachable moment...

It is considered good practice to put a simple ON/OFF switch in the B+ of each heavy DC load; e.g., starter motors, inverter/chargers, thrusters, anchor windlasses, etc. A positive way to control power should something go wrong.

And, by the way, ABYC E-11.6.1.2.1 requires such a switch in any case where the battery can provide 800 CCA or more.