Author Topic: Air pressure warning buzzer in place of a mulitmeter  (Read 1151 times)

Offline rv_safetyman

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Air pressure warning buzzer in place of a mulitmeter
« on: January 01, 2008, 08:43:34 PM »
The thread entitled "dumb question" ( has some good thoughts on trouble shooting headlight problems. 

It made me think about one of my favorite trouble shooting tools.  While I have several digital meters that allow me to do electrical trouble shooting, they are mostly gathering dust.  I use a cheap air pressure warning buzzer (with 3 foot leads/small alligator clips) to check voltage (less than $10 at most heavy truck parts houses).  It works great - especially when I am trying to check a circuit at the other end of the bus while I am working various switches, or checking breakers.

When I want to check continuity, I simply put a small 12 V battery in the circuit.  The battery I use is typically used in a home alarm system and is a 12 V unit that is about 2.5 X 2.5 X 6 inches (guessing).  I carry the components with me when I am on the road and it has saved my bacon a couple of times.


Jim Shepherd
Evergreen, CO
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Offline Barn Owl

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Re: Air pressure warning buzzer in place of a mulitmeter
« Reply #1 on: January 01, 2008, 08:49:13 PM »
Most excellent tip.


L. Christley - W3EYE Amateur Extra
Blue Ridge Mountains, S.W. Virginia
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Offline dparker

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Re: Air pressure warning buzzer in place of a mulitmeter
« Reply #2 on: January 01, 2008, 11:10:29 PM »

Another little trick that I found by accident, once when I was trouble shooting a solenoid valve on my directional boring rig (it has a long track that contains the control and power cable) I had a short that kept  blowing the circuit breaker and I could not find the bad place in the cable -- initially I bypassed the circuit breaker and nearly burned up the rest of the wiring harness -- my brain woke up and I installed a high current light (work light off a commercial piece of equipment, which operated at current draw less than the circuit breaker and the wire) in line in the circuit ... in this way when I operated the carriage the cable shorted out it did not damage the wire or trip the circuit breaker.  This method also allow the circuit to be operational so with a clamp meter (to measure current) I could find were the cable was shorting -- it would also give me the tell tale arcing ... the light would pass enough current to operate the solenoid valve (light would glow dimly) and then when the wire shorted the light would glow brightly -- you could use this on any type of circuit provided that use a load that corresponds to the voltage in the circuit, and if the load needs to be operation the light or device that you pick has more current than the tested circuit  -- if using this for ac circuits or high current dc circuits be careful ...

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Offline oldmansax

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Re: Air pressure warning buzzer in place of a mulitmeter
« Reply #3 on: January 02, 2008, 05:56:04 AM »
I kept a lot of my hand tools when I sold my HVAC business. Among them is a Fluke multimeter which has the "audible" feature. It's a handy gadget!

I know most of us would not want to pony up the dough for a new one but you can find them on Ebay occasionally for a reasonable price.