12v DC non contact wire tester?

[Timmer92]

Hi all,

My multimeter recently crapped out. I have a project on the horizon of installing LED work lights on my tractor. I'd like to purchase a non contact wire tester to make the project go easier. On the online shopping sites, many note they are AC only. I have found several that say AC and DC in the item title but then I can find no supporting DC data in the description or specs. I did find one with special instructions for testing DC, but it was one of the cheapest out there so I'm struggling to trust that it will work. Is there some limitation for which I shouldn't be pursuing this item for DC? Or maybe it's the opposite and they all will do DC and it's more of an assumption?

Thanks!

 

[GreensvilleJay]

noncontct meters sense (detect) the EM field of the 60Hz power in the wire, so AC only.
Now you could build a noncontact DC meter(BTDT) but really ,you can buy a DMM with leads for $10 any day of the week.
Heck I can buy DVM dashboard units for $3 CDN....

 

[BX23S-1]

Hi all,

My multimeter recently crapped out. I have a project on the horizon of installing LED work lights on my tractor. I'd like to purchase a non contact wire tester to make the project go easier. On the online shopping sites, many note they are AC only. I have found several that say AC and DC in the item title but then I can find no supporting DC data in the description or specs. I did find one with special instructions for testing DC, but it was one of the cheapest out there so I'm struggling to trust that it will work. Is there some limitation for which I shouldn't be pursuing this item for DC? Or maybe it's the opposite and they all will do DC and it's more of an assumption?

Thanks!

deleted from post - thank you

 

[Timmer92]

Ok, I have been reading more. It sounds like DC is power detection only, no level readings. Does that make more sense? If so, that is fine by me. I would want to confirm which wires power on and off with key, which power on and off with light switch, that I have power in general when connecting, etc.

 

[Tughill Tom]

https://www.amazon.com/Digital-Circ...ocphy=9005272&hvtargid=pla-465721548448&psc=1
This would be way more useful in wiring in equipment and troubleshooting any other issues

 

[Timmer92]

Ok, I'm ignorant when it comes to these things. It appears the clamp style works just fine with DC. I had seen these and assumed they were in the same category as "non-contact." It turns out they are a different technology altogether (they use the Hall Effect, of course ). After watching several youtube videos it looks like this is the way to go!

This one was in several youtube videos - https://www.amazon.com/dp/B00O1Q2HOQ/?coliid=I22OSIF2FI0QZB&colid=24PIC4H54X764&psc=1&ref_=lv_ov_lig_dp_it

 

[North Idaho Wolfman]

I'm going to throw a huge caution warning out here!
Just randomly seeing if a wire has voltage with or without the key being on is just a great way to fry components.
And the computer and sensors in these units ain't cheap and frying it because you taped into a feed for it won't be covered by warranty.

Get the WSM and the wiring schematic and find out what a wire or connection is, and where the proper place to connect for accessories!

 

[Jim L.]

Be aware that for the 12vdc probe to work, there must be current flowing. So an energized 12vdc conductor has to have a load for the probe to work.

 

[Timmer92]

I'm going to throw a huge caution warning out here!
Just randomly seeing if a wire has voltage with or without the key being on is just a great way to fry components.
And the computer and sensors in these units ain't cheap and frying it because you taped into a feed for it won't be covered by warranty.

Get the WSM and the wiring schematic and find out what a wire or connection is, and where the proper place to connect for accessories!

That's a great point. I had every intention of following wires to the fuse box and validating power by pulling the fuse. Alternatively, I was going to wire it directly to the battery with the proper fuse. I expect the associated advice is to actually test the draw, not just rely on manufacturing specs and/or my own math.

 

[GreensvilleJay]

I'd like to know how a 'non contact DC' probe can measure current flow and report xx amps or yyy milliamps. Distance to wire has to be critical and what if 2 or more wires( in a cable or bundle) have current in them ?
Big problem is WHO wired the tractor ? Anything other than 100% 'factory fresh' and there could( will) be problems.

 

[North Idaho Wolfman]

That's a great point. I had every intention of following wires to the fuse box and validating power by pulling the fuse. Alternatively, I was going to wire it directly to the battery with the proper fuse. I expect the associated advice is to actually test the draw, not just rely on manufacturing specs and/or my own math.

Just so you know, there is already a hot feed for ROPS work lights, it is a plug (yellow and black wires) and associated fuse (#5, 10 AMP) around or under one of the fenders, left if memory serves me right.

It is constant hot so you would have to put a local switch in or an inventive person could put a relay in that is triggered by the tail light to turn on the work lights.

 

[DustyRusty]

I have yet to find one of these no contact electrical detectors that will work on 12 volts DC. Mine will work on the higher DC voltages, but not on 12. Does this unit detect 12 volts DC current?

I use this when I need to get "into the weeds" to find the problem... https://www.amazon.com/Power-Probe-...=1576093128&sprefix=powerprove,aps,490&sr=8-3

Other than that, I use a simple 12 volt test light if I am not working around anything computerized.

 

[Roadworthy]

Many newer Kubota tractors already have a worklight connector under the rear fender. It's fed from an existing ten amp fuse in the fuse box. Unfortunately the Kubota work light is incandescent. It's also somewhere north of $100.

 

[jkcolo22]

Many newer Kubota tractors already have a worklight connector under the rear fender. It's fed from an existing ten amp fuse in the fuse box. Unfortunately the Kubota work light is incandescent. It's also somewhere north of $100.

True, but you can use that same wiring to hook up your own LED.


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[BX23S-1]

I have yet to find one of these no contact electrical detectors that will work on 12 volts DC. Mine will work on the higher DC voltages, but not on 12. Does this unit detect 12 volts DC current?

I use this when I need to get "into the weeds" to find the problem... https://www.amazon.com/Power-Probe-...=1576093128&sprefix=powerprove,aps,490&sr=8-3

Other than that, I use a simple 12 volt test light if I am not working around anything computerized.

The one i bought a year or more ago, detects 12v DC. Bad part about this one i bought is that you use it 2 to 3 times and the tiny batteries are dead in it. I looked into getting another just for chits & giggles, seems they are not sold in the USA anymore. (actually i`m going to pull the link i put in this thread because you cant get them in the USA anymore) I looked at some reviews on them today, almost every review was bad, i`ll guess that 95% of them sold didnt work when they received them. (made & sold in hongkong go figure) Luckily mine is still working, but buying batteries for it all the time just to use it kinda sucks. But i dont turn wrenches for a living anymore, so its not like i use it everyday.

I agree, the old test light is the oldest tool in the book, and it works. I do have a wireless voltage tester (with a stainless tipped probe) that snap-on sold me years ago that buzz`s when it touches 12volts, and it also has a red LED that lights up too to let you know there is voltage. This unit takes the old "N" battery. Even the "N" batteries are getting harder to find these days. Back to the old standard test light...lol

 

[lugbolt]

I'm going to throw a huge caution warning out here!
Just randomly seeing if a wire has voltage with or without the key being on is just a great way to fry components.
And the computer and sensors in these units ain't cheap and frying it because you taped into a feed for it won't be covered by warranty.

Get the WSM and the wiring schematic and find out what a wire or connection is, and where the proper place to connect for accessories!

Yup seen this a couple times this year. Tap into the can bus for 3rd function, takes out the ECU. ECU (on that tractor) was about $2500, harness about $1000. Not counting labor.

 

[Knott]

Yeah the old scope on a rope is not the safest thing on anything with a computer.
Try this, it is made for computer circuits & will not backfeed any power down a 0.5V signal wire.


https://www.amazon.com/Astro-Pneumatic-Cordless-Circuit-Tester/dp/B000IOFVUC


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[BX23S-1]

Yeah the old scope on a rope is not the safest thing on anything with a computer.
Try this, it is made for computer circuits & will not backfeed any power down a 0.5V signal wire.


https://www.amazon.com/Astro-Pneumatic-Cordless-Circuit-Tester/dp/B000IOFVUC


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I`ve got one of those, got it from the SnapOn dealer years ago.
Loved it, but i cant ever find the "N" batteries for it locally though.

 

[whitetiger]

Yeah the old scope on a rope is not the safest thing on anything with a computer.
Try this, it is made for computer circuits & will not backfeed any power down a 0.5V signal wire.


https://www.amazon.com/Astro-Pneumatic-Cordless-Circuit-Tester/dp/B000IOFVUC


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I love mine, one of the best tool purchases I ever made.