Vetus ignition switch

[Mike on the Wey]

My ignition switch has become a bit temperamental; I have ruled out the battery, starter motor and trigger wire. The Vetus part is STM9215, at a typically high Vetus price £54.20. It becomes particularly expensive because I would want two additional keys, which are £18 each. Does anybody know whether other ignition switches are compatible, and particularly if the multiplug at the back is a universal shape/configuration? And if a generic switch will do the job, which would you recommend?

[Bargebuilder]

I had a Vetus switch that kicked the starter motor into action on about every 6th try, the other 5 I just got a click, but it wasn't a switch problem at all. Are you sure it's the switch?

[Tony Brooks]

2 minutes ago, Bargebuilder said:

I had a Vetus switch that kicked the starter motor into action on about every 6th try, the other 5 I just got a click, but it wasn't a switch problem at all. Are you sure it's the switch?

 

We may well be back at the idiot multi-plugs(s) on the main engine wiring harness going resistive, so check it.

[Mike on the Wey]

2 hours ago, Bargebuilder said:

I had a Vetus switch that kicked the starter motor into action on about every 6th try, the other 5 I just got a click, but it wasn't a switch problem at all. Are you sure it's the switch?

I'm pretty sure. I replaced the trigger wire entirely (and isolated the original), so it no longer goes through a multiplug and in fact has no join between the back of the ignition switch and the starter motor. The problem persisted. I then 'borrowed' the tunnel light circuit/switch, to feed the trigger wire. So when I turn the key and nothing happens, with the key still turned I can flick the tunnel light switch and power the trigger wire. Starts every time. 

2 hours ago, Tony Brooks said:

 

We may well be back at the idiot multi-plugs(s) on the main engine wiring harness going resistive, so check it.

I think I have resistance and occasional loss of continuity in the switch. Sometimes nothing happens, sometimes it's fine. No click, just nothing. It isn't influenced by temperature or the season, or the length of time since the boat was last used. It's pretty random - I can switch off to set a lock, and it starts OK to enter the lock. Then nothing when I try to restart to leave the lock ... until I flick the tunnel light switch. 

[Bargebuilder]

My, sometimes it works, sometimes it doesn't work problem, was cured by taking the trigger wire to a relay and using the relay to take power from the battery to the starter motor. The feed from the switch, although not sufficient to activate the starter motor, was easily enough to activate the relay. No hint of reluctance to start for the last 5 years after the modification.

 

Much cheaper than a new switch!

[Tony Brooks]

Agree with both the above posts, I suspect it is undersized wire for the inrush current of both the pull in and hold in coils in the solenoid.

If anyone goes for the relay (or old car starter solenoid) option my advice is do not mount it on the engine. They tend to suffer from vibration.

[pig]

If you’re going to replace the switch, you might as well try squirting some contact cleaner (Servisol) down the keyhole.

[Eeyore]

This is compatible. https://hc-cargo.co.uk/catalog/p/180044--ignition-switch   It’s also available as a Durite part. https://www.lsengineers.co.uk/5-position-water-resistant-ignition-switch-with-unique-key-each-0-351-55.html   So the Vetus price looks reasonable.

Edited July 16, 2022 by Eeyore