Pressure/Temp Audible Warning Kit

Sep 28, 2025
128
Catalina C 30 MK1 1983 Stockton Lake Missouri
Ralph,
Yes before and after the thermostat. If I put a tee at the plug I can still use the port.
 
Jan 4, 2006
7,816
Hunter 310 West Vancouver, B.C.
That port is a little hard to see from this angle but is the plug blocking the flow from it ?

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Jan 4, 2006
7,816
Hunter 310 West Vancouver, B.C.
"Maybe" you're set to go with the temp. sensor :thumbup:.

Looks good so far, as long as those two hoses perform as shown in the flow diagram.

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Sep 28, 2025
128
Catalina C 30 MK1 1983 Stockton Lake Missouri
The only thing that happens in a hurry in sailboat repair is trouble.
I think you are right because I would have a barbed tee that I could make sure the sensor threads will be correct and I could use a tap if I need to make the correct thread size at the shop.
This way this project is it wouldn’t encroach on another system breaking in accidentally in the process.
 
Sep 28, 2025
128
Catalina C 30 MK1 1983 Stockton Lake Missouri
Is this the cooling water sensor below but I still don’t know where the oil pressure switch is.
Temperature Switch: 3/8"–18 NPT thread
Oil Pressure Switch: 1/8"–27 NPT thread

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My other possible project is to install a second installment panel here next to the engine bay compartment.
I haven’t decided on how to do this yet but the way I install the alarms can be reproduced for gauges. Or I can put in a double pole double throw switches to divert the power from one instrument panel to the other for the gauges. If I just run the gauges in parallel the voltage drop will effect the accuracy of the gauges reading.
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Jan 4, 2006
7,816
Hunter 310 West Vancouver, B.C.
Is this the cooling water sensor below but I still don’t know where the oil pressure switch is.
Looks like it but cross its wires to see if you get a HI temp. water alarm.

But now I'm getting loster :

Is there any place to install a Sierra
In your opening statement, post #1, I thought you were looking for a new location for the temp. sensor. If that is your old existing sensor, why the need for a new location for the Sierra.

Ya know, maybe I'm guilty of confusing a couple of terms here. A temp./pres. gadget which can sound an alarm is called a temp./press. switch. It contains a bimetallic element which closes a switch when dangerously hot and sends 12V to an alarm.

A temp./press. gadget which senses these parameters and turns them into a varying voltage to alter a guage readout is called a temp./press. transmitter in the industrial world. They often look the same from the exterior.

What exactly is your Sierra MP41400 Pressure/Temp Audible Warning Kit ? Sound a bit like switches to me.

So coming right back to the beginning like a dog chasing his tail, why do you need a brand new sensing point for your Shields temp switch ?

BTW Seeing as that's the original temperature gadget on the engine, I'd say it's a temp. switch. They don't install fancy transmitters on engines just off the shelf.
 
Sep 28, 2025
128
Catalina C 30 MK1 1983 Stockton Lake Missouri
Ralph,

Ya know, maybe I'm guilty of confusing a couple of terms here. A temp./pres. gadget which can sound an alarm is called a temp./press. switch. It contains a bimetallic element which closes a switch when dangerously hot and sends 12V to an alarm.
I may have called it by the wrong term.
Catalina Direct says.
Universal never provided an upgrade to add a temperature switch to the early 5411 engines, so we do not have a ready-made solution for that engine.
Tech Support

What exactly is your Sierra MP41400 Pressure/Temp Audible Warning Kit ? Sound a bit like switches to me.
Yes
I am adding an alarm to an existing system.

BTW Seeing as that's the original temperature gadget on the engine, I'd say it's a temp. switch. They don't install fancy transmitters on engines just off the shelf.
I have a gauge connected to the original coolant temperature sensor (CTS) (also called an engine coolant temperature [ECT] sensor or temperature sender unit)
1. I am add an alarms separate from the existing system.
This should be easy enough just looking for the best place to install the coolant temperature sensor (CTS)
2. And another instrument panel next to the engine compartment.
This is a little more complicated it would be like a flying bridge instrument panel. The good thing is the existing system is primitive switches, analog needle and aVariable Resistor. Although I haven’t seen the back of the existing instrument panel.
 
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Sep 28, 2025
128
Catalina C 30 MK1 1983 Stockton Lake Missouri
Yes, but the one at the engine has a (dollars to usefulness ratio) attached to it. So in the order of importance is the glow plug, key starter switch, temperature, oil pressure, amp meter gauges are what I have.
My mayor concerns is that without a 3 way switching system for two type of different brands of gauges shareing a Sender-and -Gauge only one gauge will work at a time accuratelybecause of the (Resistance Curves) may not match: A temperature gauges and its corresponding sensor must use a matching resistance/voltage curve (typically NTC thermistor values). Mixing a sensor from one brand or model with a gauge from a different brand often results in inaccurate temperature
 
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Jan 4, 2006
7,816
Hunter 310 West Vancouver, B.C.
Mixing a sensor from one brand or model with a gauge from a different brand often results in inaccurate temperatu
Only way to tell (after you've bought it of course, and POSITIVELY NO RETURNS) is to put it in a bath and check the Ω vs. temp.
 
Sep 28, 2025
128
Catalina C 30 MK1 1983 Stockton Lake Missouri
As a last resort I could just put a mark on the gauges glass where the correct temp is.
 
Sep 28, 2025
128
Catalina C 30 MK1 1983 Stockton Lake Missouri
On the side of the thermostat housing is a plug to install the coolant temperature switch for an alarm. It has a plug in mine sense there is no alarm on mine yet but I found this about 11 minutes in a video on-line. @.

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