Circuit tester

[wfolarry]

Anybody have one of these? Need a new tester & the Snap On guy was pushing this one. It's on sale. Pro's & Con's?

[Pirsch Fire Wagon]

Same as PowerProbe - just 3 times as much

[PoorUB]

PowerProbe, I never understood the need for one either. Nothing a voltmeter, some test leads, and maybe a test light can't handle.

[ecir50]

the amperage test looks like nice feature.

[86fxwg]

PowerProbe, I never understood the need for one either. Nothing a voltmeter, some test leads, and maybe a test light can't handle.

Can't test a relay with a volt meter,can't do an accurate test on a ground with a volt meter,can't power up a circuit with a volt meter!
Once u use a power probe,u wouldn't be without one!
Couldn't live without mine!

86
There's a reason it's been the # 1 electrical tool sold to techs the last 6 years !

[Coyote]

PowerProbe, I never understood the need for one either. Nothing a voltmeter, some test leads, and maybe a test light can't handle.

Can't test a relay with a volt meter,can't do an accurate test on a ground with a volt meter,can't power up a circuit with a volt meter!
Once u use a power probe,u wouldn't be without one!
Couldn't live without mine!

86
There's a reason it's been the # 1 electrical tool sold to techs the last 6 years !

I can and routinely do all that with a DVM.

[Dan89flstc]

 Deleted post

[PoorUB]

PowerProbe, I never understood the need for one either. Nothing a voltmeter, some test leads, and maybe a test light can't handle.

Can't test a relay with a volt meter,can't do an accurate test on a ground with a volt meter,can't power up a circuit with a volt meter!
Once u use a power probe,u wouldn't be without one!
Couldn't live without mine!

86
There's a reason it's been the # 1 electrical tool sold to techs the last 6 years !

I can and routinely do all that with a DVM.

Same here!

[86fxwg]

PowerProbe, I never understood the need for one either. Nothing a voltmeter, some test leads, and maybe a test light can't handle.

Can't test a relay with a volt meter,can't do an accurate test on a ground with a volt meter,can't power up a circuit with a volt meter!
Once u use a power probe,u wouldn't be without one!
Couldn't live without mine!

86
There's a reason it's been the # 1 electrical tool sold to techs the last 6 years !

I can and routinely do all that with a DVM.

Same here!

Educate me, How do u power up a circuit with a volt meter?
Explain to me how u remove a supect relay & test it with a volt meter.
Explain to me how u can load test a suspect ground with a volt meter.

86

[smoserx1]

I'll take a stab at this and I am not an electrical person.  With a DMM (or VOM) set to resistance measure resistance between relay terminals 86 and 85.  There should be a value.  Infinity indicates the relay coil is open, zero (or near very zero) would indicate a short.  Measure the resistance between terminals 30 and 87 when non-energized, the resistance should be infinity (normally open).  Apply +12V to 86 and -12V to 85, the resistance between 30 and 87 should change from infinity to near zero.  If relay has a terminal 87A repeat the test, the results should be just the opposite (normally closed).

For a ground check the resistance between the battery - terminal and the suspected ground non-energized.  Resistance should be very near zero ohms.  Set meter to a preferably low range and measure voltage non-energized for reference...should be zero.  Energize circuit and voltage should increase a very small amount but not much, perhaps a fraction of a volt.  The voltage will  increases the greater the amperage load but also the worse the ground.  This is called a voltage drop test and can be used on the positive side of a  circuit as well.

If using an analog device (VOM) the resistance needs to be calibrated by shorting the leads and zeroing the meter.  With a digital devise you can short the leads to get the resistance of the leads themselves and subtract this from your actual measurements. For doing voltage tests with an analog device the polarity comes into play as a reverse connection will make the meter respond downscale, but the procedure is otherwise is the same.

As for powering a circuit I can't explain that, I would simply use a battery.  I am not arguing an expensive tester is not better, but everyday stuff can be made to work surprisingly well.

[86fxwg]

I'll take a stab at this and I am not an electrical person.  With a DMM (or VOM) set to resistance measure resistance between relay terminals 86 and 85.  There should be a value.  Infinity indicates the relay coil is open, zero (or near very zero) would indicate a short.  Measure the resistance between terminals 30 and 87 when non-energized, the resistance should be infinity (normally open).  Apply +12V to 86 and -12V to 85, the resistance between 30 and 87 should change from infinity to near zero.  If relay has a terminal 87A repeat the test, the results should be just the opposite (normally closed).

For a ground check the resistance between the battery - terminal and the suspected ground non-energized.  Resistance should be very near zero ohms.  Set meter to a preferably low range and measure voltage non-energized for reference...should be zero.  Energize circuit and voltage should increase a very small amount but not much, perhaps a fraction of a volt.  The voltage will  increases the greater the amperage load but also the worse the ground.  This is called a voltage drop test and can be used on the positive side of a  circuit as well.

If using an analog device (VOM) the resistance needs to be calibrated by shorting the leads and zeroing the meter.  With a digital devise you can short the leads to get the resistance of the leads themselves and subtract this from your actual measurements. For doing voltage tests with an analog device the polarity comes into play as a reverse connection will make the meter respond downscale, but the procedure is otherwise is the same.

As for powering a circuit I can't explain that, I would simply use a battery.  I am not arguing an expensive tester is not better, but everyday stuff can be made to work surprisingly well.

Correct, But u CAN'T load test a ground with a volt meter! Case in point,yes u can ohm the ground BUT u can't load test the ground. One strand of wire will show continuity but,it won't show it's bad,if I load test the ground with the power probe & it blows the the circuit breaker I know it's a good ground.
23 techs @ my dealership, haven't seen there fluke meter's pulled out in years since the power probe came out.
Try one, garrentee u WON'T pull ur volt meter again once u use one!

86

[PoorUB]

As for powering the circuit, I originally mentioned jumper leads, but turn on what ever you are working on, there should be power there, if there isn't, why bother to test the relay? If I can't power up the unit, then drag out test leads and the VOM.

Keep in mind for years I worked as a commercial HVAC tech and worked on equipment large enough to walk round inside of. Trouble shooting test equipment consisted of a voltmeter and test leads. plus a occasional specialized tester for the specific equipment. I had equipment that would blow 150 amp fuses on 480 volts, plus the fuses are $100 a piece so you just can't keep stuffing fuses in to trouble shoot. Get out the VOM and start looking for the short.

As far as a suspect ground, do you mean a bad ground or a short? Bad ground, connect the voltmeter from the ground terminal of the suspect item and the other lead to ground and measure the voltage, it shouldn't be more than 1 or 2 tenths of a volt. Grounded, or short to ground, check with the ohm scale and start probing the suspected wire.

As far as I can tell there is nothing a Power Probe will do that test leads and a VOM can't. Plus, who doesn't have test leads and a VOM in the shop?

Look guys, when I first found out about Power Probe I looked into it thoroughly and decided it was just another tool I did not need. I couldn't figure out what it would do that I couldn't do with a VOM and test leads. If you are a tool junkie, buy one, I don't care!



"Correct, But u CAN'T load test a ground with a volt meter! Case in point,yes u can ohm the ground BUT u can't load test the ground."  Yes you can, I just told you how above. Turn the unit on, and test voltage drop on a powered up circuit.

[Coyote]

Correct, But u CAN'T load test a ground with a volt meter!

86

Of course you can. All you need to do is measure the voltage drop across the suspect connection under normal load (even starting). If it's a bad ground, you'll measure drop across it. I used to do it for Jim in his shop fairly often. You can check any connection point this way. Easy Peasy

Your probe is just a DVM with a power source. If you like it, that's great, but it's not needed. I've worked on a lot of bikes and never found I needed one. 

[PoorUB]

Probably the biggest difference between a Power Probe and a VOM is the Power Probe has instructions on how to test certain components and wiring. With a VOM  you are on your own unless you had a great electrical instructor at some point. (I did, the guy was awesome, made us think and taught us all kinds of tests you can do with a VOM.) Too bad I don't remember most of it!

[Appowner]

43 years as an electronic technician.  Never had the need for anything more than a VOM.  If ever I did, there are other ways to do the test than a Power Probe.  Point is, the Power Probe is not indispensable.  Consider, out of every 100 tests you do, how many could a VOM not do?  But if that is what tickles your fancy, more power to ya!  I'll stick with my $5 Radio Shack special and figure a way around anything it can't do.  Maybe fire up my laptop O'Scope.

[98fxstc]

Lot of different areas of expertise on this forum
Not all of us are a wiz with electronics or electrics
Useful post by smoserx and I have bookmarked this topic
The tools and gadgets I buy compliment the knowledge that I have to help get the job done
I did a lot of theory in school with electronics and electrical circuit theory but only basic stuff since
Not interested in going to Google to make sure I am doing something right when I tackle a job

Did you buy one Larry ?
More power to you 

[Thermodyne]

If I'm doing electrical on a Harley I seldom want more than this little kit right here.  Well, except for the breakout box sets, I would like to have a set of them.