Alternatives to Mercruiser sea water pressure sensor

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Tony63

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Re: Alternatives to Mercruiser sea water pressure sensor

:facepalm: I never said we'd find it the automotive world... But it would be helpful to start with any markings the sensor has....

If you can find ANY markings on the sensor, please post. If this is a commonly failing part, it would be fantastic to get the spec on it and get a second (more reasonably priced) option. I found a 'standard automotive part' for my engine. Merc want over $220 for the IAC, Autozone have then for $45....

Chris....

I had my receipt so my Merc dealer replaced it under warranty, lucky this time. I looked at cleaning it but it was not blocked as far as I could see. The markings on the outside of the sensor are:
8M6000623, the merc number
M0413, no idea of the reason for this number
The sensor is brass body which screws into the power steering cooler and black electronics. The black body has a green and a white dot. There is a letter "A" on the brass hex.
See photos.
thanks evryone
 

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NHGuy

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Re: Alternatives to Mercruiser sea water pressure sensor

Actually, fluid pressure sensors are used in truck and automotive applications. They are in power steering racks and automatic transmissions.
They are also found in tankless home water heaters. It wouldn't surprise me if they are in pool water equipment too.
 

alldodge

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Re: Alternatives to Mercruiser sea water pressure sensor

Agree NHGuy, I have one on my hot tube. Still like the idea of fooling it with some resistors and just remober to watch the temp gauge and replace the impeller regularly.
 

mhound

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Request to All Dodge

I have had enough trouble with the Water Pressure Sensor that I want to bypass it

The guardian system shut down power to 6 %for

my boat in heavy seas,, and it took hours to get to safety


Re: Alternatives to Mercruiser sea water pressure sensor

The problem turned out to be a bad sensor

You stated the following further up on this entry..



There are 3 pins on the connector A (BLK/BRN). B (GRY) and C (BK BLU/YEL)
Readings should red as follows at 70 degrees
A to B 31.5 ohms
A to C 42.9 ohms

Worst comes to worst it could be bypassed

Are these ohmmeter readings taken with the boat engine running (under operating conditions, or with the engine off.)

In other words would these ohm values be good to bypass the sensor ?

I have the sensor disconnected, but I get the annoying 2 beeps every minute

Do you know what voltage the sensor output should be to satisfy the guardian computer ?
 

Bt Doctur

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Untitled33_zpsea1f95ba.jpg
this is from #36 and its called a oil pressure sensor but connected to the water pump.
merc calls the electric fuel pump pressure switch a oil pressure switch. So I guess it just reads pressure .
Grey is the 5V power feed, Blk/Pk is the 5v ground lead and the Dk blue/yel is the reference lead to the computer.
I would find a donor boat to take the readings on or purchase a new sensor to measure it and then make up some resistors from radio shack
 

Bt Doctur

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notice anything similar?? Do GM cars use a oil pressure sensor?
Untitled33a_zpsc6348f01.jpg
 
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Bt Doctur

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fetch
ACDelco 213-1543 Engine Oil Pressure Sensor does it look like this
31G6hHuYzHL.jpg
 
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NHGuy

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The quote from Mercruiser shows an error. It states the oil pressure sensor measures oil flow through the oil galleries. Incorrect. It measures pressure at the sensor. Not a thread stopper, but something to know going forward.
And yes all cars including GM use oil pressure sensors.
 
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Bt Doctur

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But the point is it measures pressure , and has the same ohm`s values as the oil pressure sensor. So I`m thinking the water pressure sensor and the oil pressure sensor are one and the same unit. The GM oil pressure sensor is most likely the same part used to measure the water pressure.
pressure is pressure, oil, gas, water, air, etc
 

Scott Danforth

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I would agree with that assessment the sensor doesnt know what the fluid is, and the electronics only care about the signal.

Mercury buys sensors, they do not make them.
 

Fun Times

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Well look what I just found on ebay....Just about all the info you'd want to know about these sensors including the name of the manufacture.:) Chris you may want to save this info before it's gone.;) http://www.ebay.com/itm/Mercury-Mar...81339740492?pt=Boat_Parts_Accessories_Gear&ha

The 881879-10 pressure sensor is used on many Mercury Marine and Mercruiser engine models. MotoTron also used this sensor across many customer applications. This sensor is a 0-50 PSI, with a burst proof pressure rating of 100 PSI and a rated burst pressure of 325 PSI. Vout = 0.08 (PSI in Absolute) + 0.5. This sensor supersedes 881879-3. Sensor 881879-10 will also work as a replacement to 8M6000623.
These sensors are very robust. I have seen on applications where these sensors are mounted on closed cooling heat exchanger on Mercruiser engines where excessive static charge built up on the tank due to the flow of water and routing of spark plug wires, energy would dissipate through sensor and cause the sensor to fail. Make sure your heat exchanger is grounded!
Item #30,
http://www.mercruiserparts.com/Show_...e+and+Shift%29

One difference with the oil sensor is there seems to be a blue band around the sensor...Also see quote below for more design info inside link. http://www.ebay.com/itm/Mercury-Mari...-/181339751117
< The 881879-11 pressure sensor is used on many Mercury Marine and Mercruiser engine models. MotoTron also used this sensor across many customer applications. This sensor is a -4.7-100 PSI, with a burst proof pressure rating of 150 PSI and a rated burst pressure of 500 PSI. Vout = 0.04 (PSI in Absolute) - 0.088. I added the pin out of this sensor in pictures area so that you can diagnose your sensor prior to replacing it.


Scott, have you heard of MotoTron? Looks like they make fuel injectors too, http://www.ebay.com/sch/i.html?_from...otron&_sacat=0
$_57.JPG
 
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Scott Danforth

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Mercruiser uses (or used to use) Magneti Marelli for a while for the injectors and components. However they tend to source from most of the automotive parts bins (depending on price)
 

achris

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Thanks all for the information. It's now part of my "Merc alternatives" spreadsheet... :D
 

alldodge

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Very good info, thanks
Had another idea to bypass the sensor using a mechanical device. Take a metal pin of the appropriate size and length and stick it up in the hole. Take a Pipe cap and screw the pin up in to the sensor until the correct pressure is read. May need to drill the small hole out a bit to use a larger diameter pin, may need to experiment. Could use an oil pressure gauge to set the reading
 
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