Last winter there was a discussion about this temp and pressure audible alarm. Mine has never worked.
The oil pressure and water temp gauges work.
The engine is an original W13.
I can find the wire for the low oil pressure alarm but no place to hook it up. I’m guessing the oil pressure sender was moved on this engine and they did that because the low oil pressure switch failed. They removed the low oil pressure switch and it simply isn’t there.
My questions for the list.
Was the oil pressure switch between the engine and the oil pressure sender?
Where is the alarm buzzer supposed to be? Wiring diagram says it is in the engine compartment. The wire seems to lead to the breaker panel. I can’t find it or hear it. I could just wire a new one in if I figure out the switches.
On mine the oil pressure alarm is wired to the screw on the top of the sender. I suspect yours may be wired but the alarm is disconnected. The sender in in front of the oil filter on the side of the block.
These are pretty standard items… $30 at a auto parts store… 90 at westerbeke…
Like you my W13 engine came with working temperature and oil pressure gauges, but no audible alarms. I don’t see any obvious signs of an alarm buzzer either and I sort of wondered if maybe the alarms were the standard equipment and if you upgraded to the engine panel with the gauges they didn’t get installed. Have been meaning to see if I can figure it out, but have never had the time.
I did notice that there is a mystery threaded stud coming out of my engine just below the oil filter on the starboard side of the engine. On my boat there was a disconnected wire lying in the bilge just below it and I was wondering if that might be a sending unit for a low oil pressure alarm.
Check out the attached picture and see if your engine has anything similar.
Good luck, and let us know if you solve the problem.
I found the engine wiring harness diagram. It shows two items, 33 and 32 , the pressure sender and the pressure switch respectively. Ralph I’ll have a look for this stud.
Thanks for your help.
Tom
I did notice that there is a mystery threaded stud coming out of my engine just below the oil filter on the starboard side of the engine. On my boat there was a disconnected wire lying in the bilge just below it and I was wondering if that might be a sending unit for a low oil pressure alarm.
From what I can see, all of the Westerbeke engines come with a buzzer. I’ve told this story before and it pertains to warning buzzers. I was delivering a sailboat and it did not have a buzzer installed, just gauges. While motoring down the ICW, I heard a strange noise and quickly looked at the control panel – no oil pressure! The drain bolt on the sump had vibrated loose and drained all the oil. Needless to say, the engine was toast. If this had been equipped with an alarm, I most likely would have shut it down in time to prevent it’s early demise. The alarm is more important then gauges! It’s best to have both. That alarm should be available from most discount auto parts stores and does not have to be a genuine Westerbeke product.
Joe Valinoti
S/V IL Gatto NS30U #221
Sea Harbour YC
Oriental, NC USA
PS – As a retired mechanic, I impressed upon the owner to have one installed on his new or rebuilt engine.
I get that you can save bucks by buying an alarm from an auto supply store, but it still has to be connected to a sensor on the engine. That would have to come from Westerbeke if it isn’t already there. Correct me if I am wrong, but you couldn’t just hook it up to the oil pressure sending unit could you?
No, it has to have the proper sending unit/units. Looking at the manual and wiring diagram, the engine should have all that. Have you found the old alarm yet??
Joe Valinoti
S/V IL Gatto NS30U #221
Sea Harbour YC
Oriental, NC USA
I can’t see any sign of a buzzer unit anywhere. It could have been broken and removed years ago. My wiring is a bit of a rats nest that I haven’t had the time to figure out. Bigger alligators to slay first.
I am living in hope that the mystery connection in the picture I have posted here is the sending unit. If I put an Ohm meter between the post and ground should it read 0 when the engine is off and infinite when the engine is running?
I agree that a pressure gauge is nice, but it is the alarm that is most likely to save your bacon if things go pear shaped in a hurry.
Yes Joe I agree the alarm is probably more important than the gauge. That’s why I’m trying to fix this.
The pressure sending unit is an analogue device and goes to the gauge. The switch is on/off and goes to the alarm. Not really interchangeable.
It appears this switch has been removed from my engine. It may have failed and leaked oil so the previous owner just plugged the hole.
Looks like this switch is a very common thing at auto parts stores and cheap. I’ll look into getting a new westerbeke part first but I think any switch that fits will work.
The alarm buzzer needs to be replaced as well.
I think also need a 1/4 BSPT to 1/8 NPT adapter. I’m learning all kinds of things about this engine I really don’t want to know.
That’s right. Oil pressure switch is normally closed(opens when the engine is running and there is pressure) , the water temp switch is normally open ( closes when the temp gets too high).
I am living in hope that the mystery connection in the picture I have posted here is the sending unit. If I put an Ohm meter between the post and ground should it read 0 when the engine is off and infinite when the engine is running?
The wiring in general on my 26 is a rats nest and should be redone. Breaker panel wiring is a complete disaster.
The alarm unit should have 3 wires on it. No in theory, it should read zero when overheating and zero for the oil pressure with the engine not running as that would turn the alarm on until you get pressure. Just remember that both the oil and high temp have a wire to the alarm.
Joe Valinoti
S/V IL Gatto NS30U #221
Sea Harbour YC
Oriental, NC USA
Thanks for the image Ralph. I finally found the oil pressure switch. The only way to see it is to reach around and take a photo with a phone. It is hidden under the oil filter.
So I hooked it up and it works. The wire clip comes off easily and therefore gets disconnected when I changed the filter I suspect.
However the old alarm buzzer does not work. This is on the aft side of the breaker panel box. After I replace this all will be good.
I finally traced around my alarm circuit. Found a bad section of wire; replaced it; hooked up the dangling end in the bilge to the oil pressure sender and I now have a functioning low oil pressure alarm. It beeps when the ignition switch is turned on, and goes off once the engine has fired up. Yay!
I should be happy that all that work finally paid off except for the fact that I now have a non-trivial oil leak from the sensor. I can’t see the sensor except with a mirror, and I can only reach it around a corner with one hand at a time, so I guess all that fiddling and twisting I did trying to get the wire reattached to the sensor with one hand must have started a leak in the 35 year old sender. Looking around this forum it seems like I should be able to take the old sender to any auto parts store and get a replacement, but it isn’t obvious to me how to get the old one off (see attached picture).
I would guess the sender has a male thread that screws directly onto the engine block, but I don’t see anywhere on the old unit to put a wrench. Has anyone replaced one of these senders? Did the old one come out easily? Is it just a hand tightened assembly? That doesn’t seem to make any sense sense if it vibrates out your engine is toast!
Any tricks or tips would be appreciated. I don’t want to use the boat until this is fixed since there is no guarantee the current steady drip won’t become a flood with no warning.
Ralph: I forgot to mention that you need a 12 point deepwell socket to remove that sensor. It should have the specs scribed on it so that you can get a replacement.
Joe Valinoti
S/V IL Gatto NS30U #221
Sea Harbour YC
Oriental, NC USA
I went down to my local Part Source and found a sending unit that looks pretty much the same as the original for $20. The Westerbeke dealer didn’t have a replacement on hand and said it would be $70 to $80 to order an OEM one. Not sure if the new unit specs match exactly, but it buzzes when the ignition is turned on, and goes silent as the oil pressure builds, so I am happy to go with that. My oil leak is fixed, and I can use the boat again.
FYI: I ended up purchasing a 6 point deep socked to install it. That seemed to work just fine. The size was 1 1/16". That sure seems like an unnecessarily weird size to me. Something designed to make you go to a mechanic who would have such a thing, or at least to make you go out and purchase one. Hopefully I will never have to use it again for the rest of my life.
