Engine alarms: If you have one, how is it wired?

Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
@TomY
I just read this post by my friend @LeslieTroyer. It may give you an idea for your project. I watched it work last weekend. Very cool.

My current plans are to remove the glow plug switch and replace it with a time delay off connected to the IGN Sw. Then use the old Glow plug wire to drive a LED lamp at the panel showing glow plugs on (glow plug relay 78). Then a relay driven by the Glow plug 78 relay to 85 and 30-78a goes between switched power and alarm power.

The result of this is the glow plugs will come on with power. I won’t have to count seconds to start as the buzzers will start once the glow plugs time out. (Or listen to buzzers when glow plugs are on). Much like old Volvo’s worked. My glow plug life might be reduced by 10% but they are cheap and I can always start the engine before they time out if it is hot.

Les
 
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May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
What I did was 1) put a time delay relay to drive the Glow Plug Relay. It comes on for 18 Seconds when the ignition switch is turned on. The I hooked the power to the alarms thru another relay so it opens when the power to the glow plugs is on (timer relay output).

When I turn on the ignition switch, I get a green power light, glow plugs turn on and I get a blue light indicating glow plug on. 18 seconds later the blue light goes out, the low oil pressure alarm sounds, then I crank the engine

If the engine is warm, I crank before the timer expires. I may loose a few minutes of glow plug life but they are cheap. I also don’t miss counting one thousand on one thousand two....

The timer is a flexible solid state programmable unit fro Amazon $10-15, relays are 30-40A water proof automotive $5.

Les
 

TomY

Alden Forum Moderator
Jun 22, 2004
2,758
Alden 38' Challenger yawl Rockport Harbor
That's a brilliant idea. My only problem with it is I feel I have to have a ON OFF switch for the alarms.

The reason being that when I start the engine cold (usually getting onboard when it has sat on the mooring for several days, or more), I like to crank the starter for 10 seconds or so to pump some oil into the oil channels(is it worth it? I don't know,...)

Often I let it sit for a minute or two after cranking, then energize the glow plugs, and start it.

With the way I have it wired now, if I forget to turn the alarm on (it's easy access at the companionway), I'll know when I hit the starter and it doesn't sound.

Daily starting, I don't do the above cold start steps so the alarm will stay ON always once away from the mooring.
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
So crank for your 10 seconds and the turn off the ignition. Wait then go thru the start cycle. Only difference is you have. Glow plugs on 10 seconds more. Not a big deal.
 
Mar 8, 2017
9
Shannon Pilot House 38 Los Angles
I use a switch to turn my horn off while staring. I have a horn and buzzer and have elected to live with the buzzer because I don’t want to accidentally leave them switched off. I can hear the horn from anywhere on the boat but not so with just the buzzer. I start the engine and most of the time, manage to get the switch turned on.