Mercruiser 3.0 oil pressure alarm switch...desperate need for help!

I am about to receive the oil pressure switch for my 2005 Mercruiser 3.0...and I cannot get a clear answer, from any of the local dealers, as to where this alarm switch screws into my engine block.

I installed the water temperature switch, and it works as advertised (sits next to the temp guage sending unit, in the thermostat housing).

One local mechanic said that the oil pressure warning switch goes somewhere around the oil filter. I have looked there...and there is no obvious place for this to screw in.

Others have said that it gets 'teed' at the oil sending unit...but I doubt that Mercury shipped the engines with the optional buzzer alarm system, set up that way. I don't want to 'jury rig' a series of adapters to do this (and introduce a handful of potential leak points)...if there is a dedicated engine block point, to screw this switch into....

If anyone has a 3.0 (circa 2005) with the audio buzzer alarm factory installed...would they PLEASE take a look on their block, and see if they can locate this switch?

Added P.S...this switch, if factory installed, would have a tan/blue wire!

Re: Mercruiser 3.0 oil pressure alarm switch...desperate need for help!

Go Here...

http://forums.iboats.com/showthread.php?t=288430



Select the link for engine manuals.

Select the manual for your year and engine.

Down load said manual. (It takes awhile, they are large.)

Back the file up on storage medium.

Now search for "Oil pressure" and there is an image of the pressure sending unit and the alarm switch, piped with a "T" fitting. I suggest steel fittings and a quality pipe dope, (not teflon tape) and once assembled paint it with two or three coats of paint to prevent rusting/corosion.


*Why not teflon tape?* Teflon tape is a great product as a pipe sealer and is highly chemical resistant, however I have found that over time it does not stand up well to vibration and will eventualy leak.

Re: Mercruiser 3.0 oil pressure alarm switch...desperate need for help!

Bubba1235 said:

Go Here...

http://forums.iboats.com/showthread.php?t=288430



Select the link for engine manuals.

Select the manual for your year and engine.

Down load said manual. (It takes awhile, they are large.)

Back the file up on storage medium.

Now search for "Oil pressure" and there is an image of the pressure sending unit and the alarm switch, piped with a "T" fitting. I suggest steel fittings and a quality pipe dope, (not teflon tape) and once assembled paint it with two or three coats of paint to prevent rusting/corosion.


*Why not teflon tape?* Teflon tape is a great product as a pipe sealer and is highly chemical resistant, however I have found that over time it does not stand up well to vibration and will eventualy leak.

Click to expand...

Good evening, Bubba!

I used the search on the manual, at your suggestion...and I think that I see what you are referring to (page 4D-10). The picture is about the sending unit, but seems to clearly show the extra plumbing that can only be necessary for the pressure switch (not shown in the picture) that I am concerned about. It seems that I was wrong about this having a 'cleaner' method of installation!

Many thanks for your instructions...and for the 'heads up' on the Teflon tape!

Happy New Year to you...and anyone stopping by!

Re: Mercruiser 3.0 oil pressure alarm switch...desperate need for help!

The picture you posted is the wrong switch. The one you need has a plug in connector on the end.
Look at the picture below. #33 is the switch , #4 is the gauge sender.

Re: Mercruiser 3.0 oil pressure alarm switch...desperate need for help!

Don S said:

The picture you posted is the wrong switch. The one you need has a plug in connector on the end.
Look at the picture below. #33 is the switch , #4 is the gauge sender.

Click to expand...

Hi, Don!

I based my switch purchase on several things:

1. The wiring diagram (page 4E-4) from the 3.0 service manual...which shows a single wire hookup (tan/blue). The ground is handled through the installation in the block.

2. The description of how this switch operates is...no pressure, switch closed, and buzzer on (with key on). Oil pressure above 6 lbs, opens the switch, and the buzzer quits. If the oil pressure fails while the engine is operating, the switch closes and completes the circuit to the buzzer.

3. The place that I ordered this from (Go2Marine) listed my switch as: "Mercruiser Oil Pressure Switch, 87-805605A 1. Used For Audio Warning System."

The pigtail that you show, would make sense for the computer monitored set-ups (V-6, V-8?) I believe that the oil pressure switch in those engines, does more than trigger an alarm...and can actually shutdown the engine, independently.

What parts manual, or service manual, did your picture come out of? If I knew how to post a PDF...I would post the page I mentioned above....

BTW...Happy New Year!

Edit...P.S. All this could be resolved, if someone with the factory installed oil switch on their 3.0, could just take a picture...!

Re: Mercruiser 3.0 oil pressure alarm switch...desperate need for help!

Edit...P.S. All this could be resolved, if someone with the factory installed oil switch on their 3.0, could just take a picture...!

Click to expand...

And if no one reading this has a Circa 2005 3.0L, then what???????
It could also be resolved if you were to post your engines SN instead of (Circa 2005) since Merc goes by SN and nothing by year, 2005 doesn't mean much.

I took my picture from the Merc parts catalog (Dealer program) for 3.0L with SN range of 0W302000 to 1A0019999. Seemed about like the range for 2005.

Re: Mercruiser 3.0 oil pressure alarm switch...desperate need for help!

Don S said:

And if no one reading this has a Circa 2005 3.0L, then what???????
It could also be resolved if you were to post your engines SN instead of (Circa 2005) since Merc goes by SN and nothing by year, 2005 doesn't mean much.

I took my picture from the Merc parts catalog (Dealer program) for 3.0L with SN range of 0W302000 to 1A0019999. Seemed about like the range for 2005.

Click to expand...

The SN is: OWO39755

I guess that I left it out of the question, since the local dealer didn't seem to be able to use the SN in any reasonable, and productive, way! My bad....

Does your parts catalog give any indication as to the wire colors, for your switch?

Thanks,
John

Re: Mercruiser 3.0 oil pressure alarm switch...desperate need for help!

Hi, I would be very grateful if you could give me the Mercrusier part numbers for the oil pressure switch and the jacket water temperature switch as I have a 3.0ltr engine in a 2002 Bayliner Capri which has the wiring loom and buzzer but no actual switches. If you could let me know who i could orderer them from. Thanks for this,

Regards
John Dent

Re: Mercruiser 3.0 oil pressure alarm switch...desperate need for help!

Ayuh,... Welcome Aboard John,...

You've got to start a thread of Your Own, rather than posting your question on an old dead thread of somebodyelse's.....

You can probably find the parts you're lookin' for by clicking the Mercruiser buttons at the top of this page...

Re: Mercruiser 3.0 oil pressure alarm switch...desperate need for help!

Well, you could simplify the wiring if you just remove all your gauges and rely on a buzzer system.In this modern age who need gauges.It is the OPERATORS RESPONSIBILITY to monitor all systems .A buzzer is nice but by the time you hear it ,your toast. Ever run in low water? WHAT ,no low water alarm?.Maybe a "Underwater Object Locator" would be nice too.Don`t forget the "Low Voltage Alarm".Might save you from dead batteries. Maybe add a "High Water Bilge Alarm " so your feet don`t get wet.
Maybe we`re "Vision Impaired" and we need alarms because we`re going blind?
Sure takes the fun out of boating.

Re: Mercruiser 3.0 oil pressure alarm switch...desperate need for help!

Dogs-Life said:

Hi, I would be very grateful if you could give me the Mercrusier part numbers for the oil pressure switch and the jacket water temperature switch as I have a 3.0ltr engine in a 2002 Bayliner Capri which has the wiring loom and buzzer but no actual switches. If you could let me know who i could orderer them from. Thanks for this,

Regards
John Dent

Click to expand...

Hi, John,

I have all the part numbers, including the NAPA tee fitting numbers...and will locate them, and post for you.

Hang in there...the installation was easy, and I even added the outdrive lube monitor yesterday.

Re: Mercruiser 3.0 oil pressure alarm switch...desperate need for help!

Bt Doctur said:

Well, you could simplify the wiring if you just remove all your gauges and rely on a buzzer system.In this modern age who need gauges.It is the OPERATORS RESPONSIBILITY to monitor all systems .A buzzer is nice but by the time you hear it ,your toast. Ever run in low water? WHAT ,no low water alarm?.Maybe a "Underwater Object Locator" would be nice too.Don`t forget the "Low Voltage Alarm".Might save you from dead batteries. Maybe add a "High Water Bilge Alarm " so your feet don`t get wet.
Maybe we`re "Vision Impaired" and we need alarms because we`re going blind?
Sure takes the fun out of boating.

Click to expand...

No...what takes the 'fun' out of boating, is when the temperature creeps up before you catch it on your gauge!

I lost a head gasket on one of my boats, for this reason...and the warning alarm could have saved me. I was cruising in a narrow channel, in increasingly worsening weather, and focused on my position....

Re: Mercruiser 3.0 oil pressure alarm switch...desperate need for help!

Dogs-Life said:

Hi, I would be very grateful if you could give me the Mercrusier part numbers for the oil pressure switch and the jacket water temperature switch as I have a 3.0ltr engine in a 2002 Bayliner Capri which has the wiring loom and buzzer but no actual switches. If you could let me know who i could orderer them from. Thanks for this,

Regards
John Dent

Click to expand...

Here is the link to the post where I give you the part numbers...it is the last post in the thread:

http://forums.iboats.com/showthread.php?t=289686&highlight=3.0+alarm

Here is a picture showing you where you will find the alarm's tan/blue wire, zip tied to your cooling hose. There is the black ground wire there also...but you will only use the black wire, if you add the gear lube monitor.

There is also a picture of the correct temp switch for the 3.0...it has the red sleeve (the switch for the V-6 and V-8 engines have a black sleeve).

The gear lube bottle, with the alarm sensor, can be found on eBay:

http://cgi.ebay.com/ebaymotors/ws/e...0336692540&sspagename=STRK:MEWAX:IT&viewitem=

http://cgi.ebay.com/ebaymotors/ws/e...0290626540&sspagename=STRK:MEWAX:IT&viewitem=

Re: Mercruiser 3.0 oil pressure alarm switch...desperate need for help!

Rocky_Road said:

Here is the link to the post where I give you the part numbers...it is the last post in the thread:

http://forums.iboats.com/showthread.php?t=289686&highlight=3.0+alarm

Here is a picture showing you where you will find the alarm's tan/blue wire, zip tied to your cooling hose. There is the black ground wire there also...but you will only use the black wire, if you add the gear lube monitor.

There is also a picture of the correct temp switch for the 3.0...it has the red sleeve (the switch for the V-6 and V-8 engines have a black sleeve).

The gear lube bottle, with the alarm sensor, can be found on eBay:

http://cgi.ebay.com/ebaymotors/ws/e...0336692540&sspagename=STRK:MEWAX:IT&viewitem=

http://cgi.ebay.com/ebaymotors/ws/e...0290626540&sspagename=STRK:MEWAX:IT&viewitem=

Click to expand...

Hi,
Thanks for the info very helpful, the switch that I'm most interested in is the water temperature probe, from your links I don't seem to be able to find a part number for this item, could you please sent the details again.

Thanks again.
Regards,
John

Re: Mercruiser 3.0 oil pressure alarm switch...desperate need for help!

Dogs-Life said:

Hi,
Thanks for the info very helpful, the switch that I'm most interested in is the water temperature probe, from your links I don't seem to be able to find a part number for this item, could you please sent the details again.

Thanks again.
Regards,
John

Click to expand...

Sure, John!

Here is the eBay seller that sent me mine...he has more to sell:

http://cgi.ebay.com/ebaymotors/Merc...3002314QQptZBoatQ5fPartsQ5fAccessoriesQ5fGear

The part number is: MER 48952
Sender, Switch Assembly, Temperature, Mercruiser