Adding a push button starter to a keyed switch panel

  • Thread starter Thread starter Mark Turner
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Mark Turner

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Could I ask for the Forum's advice on the following, please.

My boat has a keyed switch for the engine in a panel set into the riser of the top companionway step. When sailing single handed it is a little inconvenient to abandon the tiller to start the engine, especially as I usually want to do this in busy waters - eg No 4 bouy in the approaches to Portsmouth Harbour or in Cowes Roads.

I was wondering whether it would be easy to fit a waterproof push button starter in the cockpit that would only work when the key was switched to the second position which would be an OK solution, and how much more complicated it would be to fit a second fully functioning three stage switch in the cockpit which would be better. The battery isolators are in the cabin so an external switch could be disabled when the boat is on its mooring.

Grateful for any help that can be offered.

Mark
PS I'm not quite as new as my thread count suggests - I've been away for a while and the webpage didn't recognise my email address, so I re-registered.
 
Mark Turner said:
Could I ask for the Forum's advice on the following, please.
Click to expand...

It depends on the engine but you dont say what it is. Access to a wiring diagram needed to give best advice

You'd still have to switch the keyswitch to the on position.

A simple button would only work if there were no glowplugs or earthing relays etc to energise.

A duplicate switch wired in parallel would work in almost all situations I think.

I'm surprised you dont have an Autohelm/Tiller pilot

You could have some way of lashing the tiller

You could start the engine a few minutes earlier when you still have plenty of sea room
 
The simplest way is to connect a switch across the main positive on the starter motor and the spade terminal on the starter solenoid. This spade terminal is the feed from the switch panel. (Putting a screwdriver across the two is one way of starting the engine without a key!)
This switch will work irrespective of wether or not the main key switch is on.
If the key switch is off then none of the gauges on the engine panel will work plus the alternator will not be charging.
So in most instances you start the engine in the normal way but if you haven't got time use this additional button.
Any switch fitted must be non-latching.

If you want the push button to only work when the main panel is switched on then take the feed from the key switch on the main panel instead of from the starter motor positive as described above.
 
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No problem to fit, in fact often done this way as starting with a key is quite a stupid way on boat. Wiring - depends how it's organized. Not complicated. If there are glow plugs you need two push buttons. May also be made so the key is not necessary.

With mercedes engine it was this way, originally: key only to engage, push button for plugs (push until it beeps), push start.
Was until someone fouled the key with his beautiful new "sailing suit" worth more than the engine. Ripped the trousers and broke the key clean off. Later on we just took the cover off, disconnected the key switch - and started engine by touching appropriate connections with powered wire :cool:
 
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If you do this is there not a danger you can blow the alternator diode? i've always read you must not run the engine with the ignition switch off for that reason. Of course the diesel will run with ignition switched off!
Talulah said:
The simplest way is to connect a switch across the main positive on the starter motor and the spade terminal on the starter solenoid. This spade terminal is the feed from the switch panel. (Putting a screwdriver across the two is one way of starting the engine without a key!)
This switch will work irrespective of wether or not the main key switch is on.
If the key switch is off then none of the gauges on the engine panel will work plus the alternator will not be charging.
So in most instances you start the engine in the normal way but if you haven't got time use this additional button.
Any switch fitted must be non-latching.
Click to expand...
 
No. There is no danger. You are not removing any of the power out cables from the alternator to the battery.
The case that you are probably refering to is the use of the 1 - 2 - Both - Off switch.
Some engines are wired so that the off position disconnects the alternator out from the batteries. That could potentially blow the diodes.
i.e. The alternator out is connected to the starter motor main supply which in turn is fed from the 1-2 - Both - Off switch.
 
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Kurrawong_Kid said:
If you do this is there not a danger you can blow the alternator diode? i've always read you must not run the engine with the ignition switch off for that reason. Of course the diesel will run with ignition switched off!
Click to expand...

Its disconnecting the battery while the engine is running that causes the problem with the alternator. Turning the keyswtich of does not do that

You usually stop a car engine (diesels included) by turning the keyswitch off!
 
Thanks for the responses.

Vic, sorry for missing out a vital piece of info! The engine is a Volvo Penta 2002, so no fancy bits at all.

I have a tiller pilot, and that's what I use at the minute but I'd rather not have to dive below to start the engine when underway, and if I can apply a simple solution would like to. I prefer sailing without the diesel even in tick over for as long and as often possible and the easier I can make starting the engine, the more I'll sail.

Mark
 
Yes, first thing to do is to "switch on" the alternator and whatever there is. So important to study original diagram for the OP's switches. At the mercedes I mentioned above it was a kind of relay or such, it only needed to be powered initially to engage; so could be made operated by same push-button. But there are many ways, mostly such things are just automotive standard now, but not necessarily so.
 
A problem with the simple approach of leaving the key-switch at the run position and taking 12v. from the switch AC terminal would be having the alarms sounding all the time.
If the switch is by-passed completely, the alarms won't work at all and the alternator might not charge.
 
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earlybird said:
A problem with the simple approach of leaving the key-switch at the run position and taking 12v. from the switch AC terminal would be having the alarms sounding all the time.
If the switch is by-passed completely, the alarms won't work at all and the alternator might not charge.
Click to expand...

Not sure why you think the alarm would sound with the key turned on. Once the engine is running everything is as per normal irrespective of which switch was used to start.
 
Vic, sorry for missing out a vital piece of info! The engine is a Volvo Penta 2002, so no fancy bits at all.
Click to expand...

Right had a quick look at the manual and the wiring diagram

A button wired between the red wire on terminal 30 and the red/yellow wire on terminal 50 of the keyswitch should do the job.

But if you switch the keyswitch to the run position earlier the warning lights will be on until you start the engine. I dont think he alarm sounds unless youpress th test button , or does it.

Ithink it will start on the button without switching on the keyswitch but the alternator probably wont generate and the warning lights, alarm and instruments will not be functional therefore not advisable.
 
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Talulah said:
As yes. Understood. See what you mean. You know your going to start the engine and have the key turned on in prep. The annoying noise will now force you to start it before you really want to.
Click to expand...

Does the alarm sound as soon as switched on or only if the test button is pressed ? If it does sound that will be more annoying than having the engine idling for a couple of minutes


A duplicate switch wired in parallel will solve the problem if there is one
 
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Vic,

Thanks.

On my boat the alarm does not sound when the "lights are on", only when tested, and I'm happy to have the key in that position with the engine off, and so ready to go "on the button" when the Queen's Harbour Master insists I have to have my engine running.

It sounds as though I can rig something up to test before I make holes in the cockpit to take the button so I'll give it a go. That's one job on the to do list that I can half tick as now knowing what to do. I'll report back when I've done it, but for now, thanks.

Mark
 
VicS said:
Does the alarm sound as soon as switched on or only if the test button is pressed ?
Click to expand...

I don't know on that engine.
On our first boat the alarm sounded all the time the key was turned on whilst the engine wasn't running.
On the current boat we don't have an alarm. Removed due to corrosion.
On a lot of boats they never work irrespective due to corrosion.
(Actually, on the current boat all of the warning lights are removed due to corrosion. Gauges OK: Voltage, Oil Pressure and Temp work OK.)
 
Mark Turner said:
Vic,
... and so ready to go "on the button" when the Queen's Harbour Master insists I have to have my engine running.
Click to expand...
Slight thread drift. A lot of people don't realise that not only must their engine be running between No 4 and the Ballast Pole it must also be engaged.

"All craft fitted with engines, when navigating in the Approach Channel to Portsmouth Harbour,are to proceed under power between No 4 Bar Buoy and the Ballast Beacon."
 
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