Home FAQ General Buy now Fitting instructions, Townace

Ace Answers engine temperature alarm.
Fitting instructions, Estima.

If yours is an experimental/tinkering version, remove the lid, set the screw aside and use a rubber band to hold the lid on until you've finished tinkering. Notice how the cable can be disconnected inside the unit at the white push-on connector. Make a note of the switch settings or you will lose track of your tinkering!

To connect the alarm cable you must get access behind the instrument panel. You don't need to remove it or even disconnect anything. Just pull it out of the dash and turn it over to see the terminal screws behind the temperature gauge. Advice is available on the web. The best I can offer is as follows... (Models vary. Suggested improvements welcome. I own a Townace, not an Estima)

Decide where you want the alarm box to be, thread the cable up behind the dash so it will end up in a suitable route when you've replaced the instrument panel. More access to it will be needed during initial adjustments.

Connect to the three terminals behind the temperature gauge as shown. Your alarm may have a brown cable with Yellow, Black and Red wires, or a black one with Blue, Green and Red wires. Refer to the correct illustration. Yellow or Blue (sensor connection) nearest the corner, Black or Green (0V) in the middle, Red (V+) is the third.

Turn the blue adjustment knob fully anticlockwise so that the alarm will sound at a relatively low temperature. When you switch on you should hear a quick blip from the alarm. Once the engine gets hot you will notice the gauge is reading differently. Donít panic! The engine is almost certainly just the same, itís the gauge thatís telling you something different. Whenever the alarm sounds turn the blue knob clockwise a small amount and it will stop. After a few trips you will find a setting where it only sounds occasionally, as a warning. If you want the alarm louder then take the cover off and make a small hole in it - having the box sealed protects what's inside but reduces the loudness a lot..

With a very hot engine don't be surprised if your gauge almost goes into the red. However DO NOT take the red line as an indication of safe/unsafe operating temperature. It's not that easy. The gauge now tells you about temperature changes, and permits some comparison between similar cars - but the indication will also be sensitive to manufacturing variations between engine sensors and the gauges themselves. You can easily and safely disconnect the alarm (one screw, pull off connector inside) if you want to be reminded how the gauge performed before.

Because I've been asked so many time I provide this calibration as the best I can do, but please don't take it as a highly accurate.
Before on the left, after fitting a Mason alarm on the right...calibration.

For "tinkering" refer to technical notes elsewhere, or just ask!

I am committed to correcting any faults, and making improvements, within the alarm unit, but cannot accept responsibility for how the alarm is used and therefore for the degree of protection it provides you.

Dave Mason, revised 12 March 2007.