After my heat exchanger leak over heating issue, it seems my temperature sender is not doing the job anymore. This week-end after some troubleshooting, I discovered two things:
- Brown cable: the expected temperature sender plugged at the thermostat housing is not connected to anything in the back (I guess it failed previously and the PO replaced it a different way)
- Yellow cable: plugged back to the temperature gauge on the engine panel
Now I have 3 questions:
- Why does it look like I have two senders? Is it a normal setup?
- Which one should I replace by a new one and which part to get back to an optimal situation?
- I would like to get this data on my NMEA 2000 network, which way do you advise to go to achieve this?
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Ludovic François
Hotel Catalina - Catalina 36 Hull #883
Marina Del Rey, CA
To answer question #1, I suspect that one of these is the temperature gauge sender, and the other is a sender for a high temperature alarm. That became standard on later C36s, I believe, but not on earlier ones (such as ours, where we had to retrofit a high temperature alarm). If the yellow cable is going to the temperature gauge, that would make sense. You didn't indicate whether your gauge was actually displaying readings when the engine is on... is it?
The alarm is a very nice thing to have; I suspect few of us regularly check the temperature gauge while motoring....
So, it the upper sender is in fact the sender for the high-temp alarm, it should be connected to a buzzer of some sort.
Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY
No the temp gauge is not displaying any reading, if I short the yellow cable to the ground (engine), it goes all the way up on the gauge.
What is strange the top cable "brown" looks like not getting all the way back to the engine control panel.
Ludovic François
Hotel Catalina - Catalina 36 Hull #883
Marina Del Rey, CA
[quote=ludo]No the temp gauge is not displaying any reading, if I short the yellow cable to the ground (engine), it goes all the way up on the gauge.
What is strange the top cable "brown" looks like not getting all the way back to the engine control panel.[/quote]
OK, so looks like you've diagnosed it as a bad sender unit. Had the same problem myself; we got a replacement from Catalina Direct: www.catalinadirect.com/index.cfm/product/3245_843/temperature-sender-universal-diesel-14-npt.cfm
As to what appears to be the high temp. alarm, you could test it by suspending it in a pot on the stove and heating it up to boiling, hooked up to a test lamp to see if goes on. Then, of course, you'll need to find an alarm buzzer to connect it to.... We got that too from Catalina Direct:
www.catalinadirect.com/index.cfm/product/2384_843/alarm-module-dual-tone-engine-panel.cfm
You do want a buzzer, not just an idiot light. If you're cruising along on autopilot rather than sitting behind the wheel and keeping an eye on the instrument panel, you probably won't even notice a high temperature warning light come on until the damage has already been done from an engine overheat.
By the way, one more tip to prevent overheating damage caused by operator stupidity (don't ask me how I know!): Put a hook on the inside of the access door for the engine raw water intake seacock, and always store the key for the engine there. That way, you (hopefully) force yourself to remember to open the seacock before starting the engine.
Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY
Ludovic - I'm using a NoLand Engineering RS11 to get temp to NMEA 2K (actually seatalkng via an adapter in my case). I also installed a dual idiot/gauge for oil pressure. I see Oil Pressure, Temp & RPM's right on a i70 located at the helm.
Les & Trish Troyer
Mahalo
Everett, WA
1983 C-36 Hull #0094
C-36 MK 1 Technical Editor.
Commodore
Les,
For the oil pressure, do you have a write up with a list of parts somewhere on the forum? What gauge/sender did you use for this? Any online reference?
About the RS11, I am looking at it, also a friend is building this https://hackaday.io/project/11055-kbox, so it could be an alternative to do the same job as the RS11 with way more homework on my side :)
Ludovic François
Hotel Catalina - Catalina 36 Hull #883
Marina Del Rey, CA
If it like my set up. The upper sender is for the light. It has a slip on type connector. It will read will be open on a Oms meter until "Hot".At that point it closes and provides a ground. Not sure what temp "Hot" is..
Sender that has nut on top should be for temp gage. It will change Oms with temp change.
Chuck Lennox
97 MKii Ventura Ca
Island Girl Hull #1611
The high temp sensor provides a ground which sounds the soanalert that is located on the Capitan's display at the helm. This soanalert has 2 tones - the steady tone indicates low oil pressure and the intermittent tone indicates high water temperature. To test which sender unit is the high water temp remove the wire from the sensor and hold it at ground with the engine running. You should hear the soanaert making pulsating tones and the light next to it will be lit. From your describing it is possible that someone reversed these 2 wires at the engine hot water detectors.
Sail La Vie 1999 Catalina 36 MKII, M35B-17031, Coyote Point, San Mateo, CA
About Sail La Vie
Catalina Direct has this info for testing your temp gauges.
http://www.catalinadirect.com/index.cfm/feature/161_544/temperature-gauge-test-procedure.cfm
it's pretty simple.
Chuck Lennox
97 MKii Ventura Ca
Island Girl Hull #1611
Catalina Direct has this info for testing your temp gauges.
http://www.catalinadirect.com/index.cfm/feature/161_544/temperature-gauge-test-procedure.cfm
it's pretty simple.
Chuck Lennox
97 MKii Ventura Ca
Island Girl Hull #1611
Chuck,
thanks for this engine temperature sending unit test procedure!
just what I was looking for. My engine coolant temp goes up to 175°, last year always 160°
I've R&R the HX, boiled it out. Changed the Sherwood pump rotor. Checked intake they hull, new hose, checked the raw water strainer. Replaced a number of original hoses. Still reads 175°!!!
so, now I'm going to R&R the temp sending unit.
And unrelated, R&R water heater with a new Sherwood stainless steel water heater next week! Old one leaking. Always something to fix!
Steven Jones
C36/375IA FaceBook group administrator
C36/375IA Jib Sheet Editor 2012
Seal Beach, CA, USA
C36 #2164 Maléna 2003 Mk-II SRig/FullK, Long Beach, CA
stevenjones21@gmail.com
I may have commented on this before. The Gulf of Mexico sea water temperature here in sunny Florida is about 20-25 degrees hotter in the summer than in the winter. I found my engine runs about ten degrees hotter in the summer then the winter. 160 in the winter and 170 in the summer.
__/)__/)__/)__Capt Mike__/)__/)__/)__
Punta Gorda Florida
1990 Std WK M35 Hull #1050