Adding mercruiser engine alarm - 2002 3.0L

mvoellinger

Cadet
Joined
Nov 9, 2008
Messages
10
I have the 3.0L without the engine alarm. Id like to add it - from what I can see I need about 5 parts - the oil switch, the T for the oil pressure switch & sender, the water temp switch, the buzzer and the new lube resevoir (although Id be happy without this - I check it frequently enough its more just so I cant lose oil pressure/overheat between checking the gauges).

Has anyone does this? It looks like all the wiring is in place except for the oil switch, where does it plug into?

Does anyone have part #s and prices? Thanks!
 

Rocky_Road

Lieutenant Commander
Joined
Oct 8, 2008
Messages
1,798
Re: Adding mercruiser engine alarm - 2002 3.0L

I have the 3.0L without the engine alarm. Id like to add it - from what I can see I need about 5 parts - the oil switch, the T for the oil pressure switch & sender, the water temp switch, the buzzer and the new lube resevoir (although Id be happy without this - I check it frequently enough its more just so I cant lose oil pressure/overheat between checking the gauges).

Has anyone does this? It looks like all the wiring is in place except for the oil switch, where does it plug into?

Does anyone have part #s and prices? Thanks!

I did the whole thing...not to bad, since my boat had the buzzer already under the helm. The tan/blue wire was strapped near the thermostat, for the temperature switch. There was another tan/blue wire in the same general location for the gear lube bottle. But I never could locate the tan/blue wire for the oil pressure switch.... What I did was run a new wire from the temp switch over to the oil pressure switch:

14tygk4.jpg


Here is the oil pressure switch on a tee fitting:

2zxow43.jpg


Do not make my mistake and use a short brass nipple from the tee to the engine block. Within one hour of running, it fatigue cracked (either too tight, or the suspended weight of both sending units) and I lost almost all of my oil! I replaced it with a short stainless steel nipple...although plain steel might be easier to find.

I bought a new gear lube reservoir from eBay, that had the float unit installed.

As for the temperature switch, I used the correct Mercruiser (red band) unit. Make sure that you don't use the black banded one...that is for the V-6 and V-8 (higher temperature trigger).

Here is a picture of the buzzer...you might have it under the helm:

2ly5vo8.jpg


You will find a black ground wire with the tan/blue wire near the gear lube reservoir...but it is only needed for the lube monitor. Both the oil and temp switches ground through their threads (don't use teflon tape).

30ijr40.jpg


Hope that helps!

Happy boating!
 

Mischief Managed

Lieutenant Commander
Joined
Dec 6, 2005
Messages
1,928
Re: Adding mercruiser engine alarm - 2002 3.0L

Excellent reply, Rocky_Road. Comprehensive posts like that are a perfect example of what's good about the Internet.
 

Rocky_Road

Lieutenant Commander
Joined
Oct 8, 2008
Messages
1,798
Re: Adding mercruiser engine alarm - 2002 3.0L

Welcome to boating!

As an alternative, there is an alarm kit right here on iboats:

http://www.iboats.com/Cole_Hersee_M...331207058--**********.339373215--view_id.3876

It is not made by Mercury, and I have no idea what temperature the switch is set at, but it may be just fine. The oil pressure switch is pretty universal...most are set for around 4-6 PSI.

Give the link a 'look see'...!
 

elkhunter338

Master Chief Petty Officer
Joined
Jun 27, 2009
Messages
818
Re: Adding mercruiser engine alarm - 2002 3.0L

I to say do not use brass fittings for the oil pressure sender, I to had a brass pipe crack and loose some oil. Put a galvanized steel one on.
I used a automotive 15psi oil pressure switch wired to a warning light and buzzer on the dash.
I used a automotive electric fan switch turn on at 190 deg. to operate the buzzer and light if the engine temp reached 190 deg. I run antifreeze in my engine block with a 160 deg. thermostate.
I have a 2007 3.0 in a 1984 boat.
 
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