Audible engine is too hot alarm

[SiFi]

I want to fit an engine overheat audible alarm to my (Lister Alpha) engine. I have a gauge but I want something that I can't miss. Something simple, reliable and noisy!  Are there different types of sensors? Some for a gauge and others that are a switch for a warning light or alarm.

Edited November 3 by SiFi
clarification

[Tony Brooks]

How about something like this https://www.amazon.co.uk/Universal-Temperature-Sensor-Adapter-Aluminum/dp/B088WZYZFN

 

Buy your own switch, cable, terminals and buzzer. If you already have an overheat warning lamp, you are likely to find you already have what you want, but it has never operated. 

 

Some cylinder thermostats can be adjusted up to 90C so one of those strapped to the top hose might work, but I would prefer a slightly higher temperature.

[SiFi]

Hi Tony, thanks for your reply, there is an overheat warning lamp but either it is not working or I don't see it. I have a weak hose connection on the gearbox oil cooler that has twice failed. My uncertainty is did it fail because the engine overheated or did the engine overheat because the hose failed. Any way I will investigate just what I have at the moment. It may just be that my sensor isn't working. Thanks again

 

I did find this engine temperature sensor and alarm that measures the temperature at the cylinder head rather than coolant. https://ebay.us/m/zpP2v2 ...

[Tony Brooks]

Just now, SiFi said:

Hi Tony, thanks for your reply, there is an overheat warning lamp but either it is not working or I don't see it. I have a weak hose connection on the gearbox oil cooler that has twice failed. My uncertainty is did it fail because the engine overheated or did the engine overheat because the hose failed. Any way I will investigate just what I have at the moment. It may just be that my sensor isn't working. Thanks again

 

I did find this engine temperature sensor and alarm that measures the temperature at the cylinder head rather than coolant. https://ebay.us/m/zpP2v2 ...

 

Yes, but there is no evidence that it has an audible alarm, which is what you asked for, which is why I did not give a link to cheaper copies on Amazon/eBay.

 

If you have an overheat warning lamp, then there should be an overheat temperature switch on the engine. Usually on top or into the side of the thermostat housing or in the head very close by. It may be a combined unit with a sender plus switch, in which case it will have two or three terminals. In general terms (not Lister Alapha specific) if you locate that switch and touch the cable fitted to it to negative (engine metal?) with the ignition turned on, then the lamp should light and the buzzer sound.

 

If it does, then the switch is faulty.

 

If it does not, then there is a wiring fault somewhere between the ignition switch and overheats switch.

 

If the lamp comes on, but the buzzer does not sound, then either the buzzer, buzzer wiring, or diode pack has failed. In that case, I would wire any 12V buzzer between the ignition on terminal on the ignition switch or the warning lamp bulb and the engine switch. Plenty of buzzers on the net from about £2. This bypasses the diode pack that allows the mariniser to use one buzzer to monitor three potential faults.

[SiFi]

Thanks for your insight. There may well be an audible alarm as you can see I'm in the dark at the moment.

Edited November 3 by SiFi

[Alan de Enfield]

13 minutes ago, SiFi said:

Thanks for your insight. There may well be an audible alarm as you can see I'm in the dark at the moment.

 

When did you last charge your batteries ?

[SiFi]

My batteries are good.

[MtB]

29 minutes ago, Alan de Enfield said:

 

When did you last charge your batteries ?

 

Or just open the curtains! 

 

 

[jonesthenuke]

I have used these for monitoring the temperature of the alternators on our boat. The are 12 V, cheap and work fine. They have relay contacts that can be used for an alarm or beacon lamp

 

https://www.ebay.co.uk/itm/136154701828?_skw=STC-1000&itmmeta=01K94P63MFHT7PZ5V0M3K31423&hash=item1fb373e004%3Ag%3ANX4AAeSwJmZodbsL&itmprp=enc%3AAQAKAAAA4FkggFvd1GGDu0w3yXCmi1fecmW23pEu9pVEfZpVJ7bzwzHjqoV3mPIki5vFBDnxZWyaH3kZEeN6TeYzasdx2Tha96P3obYYFzyMMpG7RgCJT7wllF8xgGJvDQDydONm6DdlzSPsUj%2FP%2FzsTmMTmT%2BsoxVhYqkqwkYUKAa6lOR9HahZLtRtTEXt8sxWTJ43xDdQe2fymEfVEyljLenuzYVIzQKAgXUSQhyWqlt4mipRvNvwRKvJ5INMHo5ucTXaY8E%2FtTYKNP8SyQtDD5wH8yVHQ3jlb5espY6x%2FXYtSoOwm|tkp%3ABFBMvLqYlslm&var=435152306614

[jonathanA]

The temperature warning light and buzzer fitted to the standard lister control panel is usually loud enough to alert me to a problem. So if you hsve a proper lister control panel it will be worth investigating why that's not buzzing and or fitting a louder/extra buzzer if you need one. 

 

Personally I wouldn't be looking at 3rd party strap on solutions, better to get the standard system working.

 

The water temp warning light switch and sender for a gauge are usually separate devices on the side of the thermostat housing. If fitted. 

 

I've found the temperature warning light switch lister use to be a bit vulnerable as its easy to catch as you clamber round the engine and either knock.the wires off or break it.

 

Is the oil cooler problem  the rubber boot coming off ? I had that happen to me after replacing one that had split. You have to make sure the outside of theoil cooler tube is very clean  and push the boot on as far as itvwill go which isn't very far then tighten up the jubilee clip tight. Then tighten it a bit more then take it off because it's not on square and do it again until the boot and clip are square and properly on the tube.  😅

Edited November 4 by jonathanA
Sp

[Peugeot 106]

You probably have a thermistor and BMI giving you the alarm. If you PM me with your email address I can forward to you correspondence and instructions from Peter Thompson regarding replacing the thermistor and BMI with  a normally open switch (available from Sleeman Hawken)

Peter used to refurbish and marinise these  engines for Lister Petter

Agreed the wires fall off the thermistor easily so check as Jonathan suggests

Just found my diagram!
 

[jonathanA]

thought this pic might help you. this is my temp switch at the front and an after market gauge sender with the yellow wire/blue connector.  my engine has the lister cauliflower take off which is where the temp warning light switch is fitted.  The part number i have for the temp warning switch is 329-15140