Adding an alarm to Oil sender

[zinahewitt]

Hi All,

I have an old boat from the 70s, 1975 Dufuor 34.

The boat has an MD2B engine.
The engine has a sender for oil pressure.
The sender is tubed up all the way into a nice looking gauge.
The Gauge doesn't have anything electric except for a -+ for a light.

My question is how do I add a low pressure oil alarm
or should I not bother as looks like they did not in the 70s.

My main problem is the gauge is on the inside of the boat, so no one would ever look at it while the engine is running
Therefore I thought it might be prudent to add the alarm, either audible or a light or both.

Thanks for any suggestions.

 

[Project_Mayhem]

You would add a T to the hose or fitting and an oil pressure switch for the electrical connection

 

[marcham]

Oil pressure monitoring is not as straight forward as an oil pressure alarm switch or a coolant temp sender. With oil pressure, there are shocks, rapid fluctuations, etc.... (think water hammer in your house?). Depending on where you tap the oil lube system, you may need a damper to avoid the surges and avoid damaging the oil pressure sender.

 

[Allan12210]

That looks like an aftermarket automotive oil pressure gauge that I had in an old car of mine. That tube broke behind the gauge and I ended up with an oil saturated carpet. What a mess to clean up. There are electric versions of those gauges available. The sender mounts to the engine and just wires go to the gauge. You might search around the internet and find a combination oil gauge with low pressure alarm or as suggested add a Tee fitting at the engine to a remote buzzer sender too. My Yanmar had the buzzer already, so I added an electric gauge sender that I could see in the cockpit. Same for the water temperature sender.

 

[marcham]

That looks like an aftermarket automotive oil pressure gauge that I had in an old car of mine. That tube broke behind the gauge and I ended up with an oil saturated carpet. What a mess to clean up. There are electric versions of those gauges available. The sender mounts to the engine and just wires go to the gauge. You might search around the internet and find a combination oil gauge with low pressure alarm or as suggested add a Tee fitting at the engine to a remote buzzer sender too. My Yanmar had the buzzer already, so I added an electric gauge sender that I could see in the cockpit. Same for the water temperature sender.

Nice! Do you happen to know the part no you used for the sender? I assume you had to install a BSPT to TP thread adapter?

PS: is that a small tear in the belt or a bit of dust?

 

[Allan12210]

Nice! Do you happen to know the part no you used for the sender? I assume you had to install a BSPT to TP thread adapter?

PS: is that a small tear in the belt or a bit of dust?

Thanks. I put that in in 1992, so my memory may be a bit shaky. The sender came with the gauge. In fact it was an entire set of gauges and senders. Luckily I found alternative ports on the Yanmar for the additional sensors. That oil sensor location is where there was a small pipe plug with an Allen head that I removed. While standing in line at my local Kragen's to buy the gauges, I noticed a package of NPT to Metric adapters. I thought they might be handy so I bought them too. Turns out I was right. That is the brass fitting in the picture between the engine and the sender. That mark on the belt is residual gray spray paint. Here is a shot of the water temperature sender location as well. That was handy a few times as I could see the water temperature starting to creep up and address it before the audible alarm went off.