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Warning buzzers and sensors

by Phil Lapin / CPPC Tech Committee and President

Do you constantly have one eye on the temperature gauge of your car while driving?

Of course not! I have had several bad engine problems over the years when gauges would have told me something was wrong – but I was watching the road.

buzzersThe same applies to turn signals in vintage vehicles – which often have poor or no lighting indicators when the signals are on. Down the road you go, with your signal incessantly flashing away! These kinds of problems can be real safety issues, yet are corrected very easily thanks to modern electrical and electronic devices.

The key element here is to add a small buzzer as a warning device."Piezo electronic buzzers" are something we have all heard – but perhaps not thought of for our antique cars. I purchased a package of 5 buzzers through Amazon for a total of $8.99 – a whopping $1.80 each. They are totally enclosed, and about the diameter of a quarter by about ½ inch high. The ones I purchased have leads on them, and they will work with from 3 to 24 volts DC. Changing the voltage merely alters the pitch and volume slightly – perfect for our cars! Double faced foam tape secured them under the bottom of the dash. Just be sure to keep the polarity of the wires correct.

Application one: turn signals! The flasher unit on my 6v pos ground vehicle is an "electronic one". It has a third terminal on it which was unused. It turns out that the terminal puts out voltage whenever either direction of turn signal is on. I simply hooked one lead of the buzzer to that terminal, and the other to ground. Now I have an audible warning that my turn signal is on. If you do not have a flasher unit like mine, simply use 2 buzzers, with one connected to the wiring for each front turn signal light. The end result is the same. Do not connect to the rear turn lights, as these often interact with the brake lights.

sensorApplication two: engine temperature. I recently had a new freeze plug come loose – and my engine temp went up somewhere over 212F before I saw steam. Another member just had the same experience as me. An audible warning is an excellent insurance policy against this type of event. Using the same buzzer as described above, it is coupled to a temperature switch. I purchased two normally open thermal switches from Amazon for a total of $6.29. The ones I chose are very small (about ¾" long, with two leads attached. They can be ordered in a variety of temperature settings. 90 degrees C is perfect – it will close contacts and activate the buzzer at about 200 degrees F. It can easily be tucked under any small projection on the head or block, and then wired into one of the buzzer leads.

Here is what I ordered from Amazon (in lots of words!) Buzzer: "DIKAVS 5 pcs 3-24v Small Enclosed Piezo Electronic Buzzer Alarm". $8.99 for 5. Thermal switch: "Uxcell KSD9700 Thermostat 90 degrees C Normally Open Temperature Switch. N.O. 5A metal Bimetal Temperature Controller" $6.29 for 2.

Drive Safely!