Even better than a meter

[deandec]

Ok, I am uneducated in things electrical although I have done a fair amount of installations of AC and DC and repairs and own several cheap multimeters.

I have a single wire test probe of my Dad's (note that I am over 75 years old) that I am not sure how to use.

First, why does it need to connect to a battery?

[Soppy]

I prefer my old fluke 77 multimeter. It's much lighter and easier to read than my simpson 270. Since I carry the fluke with me I really don't need a test light.

[YC1]

Originally Posted by deandec

Ok, I am uneducated in things electrical although I have done a fair amount of installations of AC and DC and repairs and own several cheap multimeters.

I have a single wire test probe of my Dad's (note that I am over 75 years old) that I am not sure how to use.

First, why does it need to connect to a battery?

If you are talking about a probe with a light bulb in the handle you do NOT need to connect to a battery. You normally ground the wire via the alligator clip on one end and use the pointy end to probe things. If it lights up, you have power there.

Use electrical tape to cover the probe down to near the point. No sense in letting the smoke out of adjacent components.

Sharpen the probe by turning it against a bench grinder or whatever pops your corn.

[deandec]

Originally Posted by YC1

If you are talking about a probe with a light bulb in the handle you do NOT need to connect to a battery. You normally ground the wire via the alligator clip on one end and use the pointy end to probe things. If it lights up, you have power there.

Use electrical tape to cover the probe down to near the point. No sense in letting the smoke out of adjacent components.

Sharpen the probe by turning it against a bench grinder or whatever pops your corn.

This helps me. I will start using it. But will keep the smoke in the circuit!

[GypsyR]

To further confuse things, SnapOn sells a little test light with no pigtail wire. You hold it in your hand and press the probe tip to what you are looking for power on and with your other hand touch something that's grounded on the vehicle. It then lights and makes a noise. I have found that on many cars I don't have to use the other hand and it will let out a small chirp anyway. SUPER handy for checking fuses. Not cheap though.

[Busskipper]

Originally Posted by GypsyR

To further confuse things, SnapOn sells a little test light with no pigtail wire. You hold it in your hand and press the probe tip to what you are looking for power on and with your other hand touch something that's grounded on the vehicle. It then lights and makes a noise. I have found that on many cars I don't have to use the other hand and it will let out a small chirp anyway. SUPER handy for checking fuses. Not cheap though.

When you said Snap On Most know it’s not CHEAP. $$$$$

[Mudfrog]

Originally Posted by GypsyR

To further confuse things, SnapOn sells a little test light with no pigtail wire. You hold it in your hand and press the probe tip to what you are looking for power on and with your other hand touch something that's grounded on the vehicle. It then lights and makes a noise. I have found that on many cars I don't have to use the other hand and it will let out a small chirp anyway. SUPER handy for checking fuses. Not cheap though.

I have a non contact AC test pen that works similarly. I forget the exact specs but I believe it senses voltages between about 90 and a 1000 volts. Very handy for making a quick check to see if a wire is hot.



But, I sure didn't know there was a similar device made for checking DC voltage. Can see that it would be handy at times so I might have to look into this.

Edited to add: Re-read your reply. Sounds like the Snap On has a probe that has to make contact with a bare wire/terminal/fuse holder before you can get a reading. Not quite the same as what I was initially thinking.

[GypsyR]

No, not quite the same, it requires actual contact. I have an AC sensor like that. Mine takes a battery. The SnapOn test light doesn't take a battery by the way. It's part #EECT200 if you're still interested.
I gave one to my brother in law for Christmas last year and his initial reaction was "What the heck do I need this for?" Now it's his go-to fuse checker he can't live without. I have to confess about I use it for is fuses. I usually go to other tools for anything more electrically complex. But it drops into a pocket and has no dangly cord to hang out.

[FIRE UP]

Well,
As usual on RV forums, too much waaaaaaaaaaaay overthinking of a simple subject. 12V probes have a place in the auto world of electrical diagnostics, as do meters. Been *probing* wires to check for signals/hots for decades and as of yet, no 3 alarm fires, no complete dyeing off of any electrical system due to supposed *corrosion* that would/could be the result of probing insulation and all that.

A very large percentage of the time, when a wire is probed, as in POKING the insulation, that insulation is resilient enough that, when the probe is removed, the insulation sort-a closes back up. Now, it doesn't HEAL, it just closes. But, even on OLD insulation, with a sharp probe, there's just not that much concern of intrusion of moisture and or corrosion, unless the probed point is UNDER WATER for its remaining life. Then, all bets are off.

But, a probe certainly has its place in the electrical investigative world. But, as those that use them know, it's only a confirmation that there's either a signal/hot, or not. It does NOT tell you what kind of actual voltage is there.
For that kind of info, yes, you need some form of a meter. There are probes out there that are basically combo units, a probe AND a meter, such as the example below:

https://www.amazon.com/Power-Probe-I...9489743&sr=8-6

I've got a 12V probe and a meter, in every vehicle, motorcycle, motorhome and boat that we own. Each testing tool has its value.
Scott

[jimmoore13]

No argument with the recommendation.

Get a multi-meter, too. Harbor Freight sells them, too.
You need to be able to test continuity and so on. And it's nice to be able to check 120 or 240 volts as needed.

But for quick and dirty, the logic probe makes sense.

[LETMGROW]

Originally Posted by R.Wold

Ah yes, and speaking of old reliable....

I have a Snap-On meter similar to your ohm meter but mine (MT 826) will test dwell (4 / 6 / 8 cyl.), volts, ohms and has two RPM scales ( High / Low ). I bought it new in 1963 and still use it on occasion.
Lynn

[Roy-c]

If you have to ask how a test light works then you shouldn't be messing with anything electrical

[theoldwizard]

Originally Posted by Gary RVRoamer

It doesn't require any more (or less) holes in the insulation than a meter with probes. The tester has to be able to touch the wire itself, so you probe at connections and other exposed points. Poking thru insulation to reach the bare wire is a last resort (but once in awhile the only way to get 'er done).

Liquid Electrical Tape



Probably not worth the cost for the "average" RV, but this is the ULTIMATE way to pierce a wire

Insulation piercing probes

[GypsyR]

Originally Posted by FIRE UP

when a wire is probed, as in POKING the insulation, that insulation is resilient enough that, when the probe is removed, the insulation sort-a closes back up. Now, it doesn't HEAL, it just closes. But, even on OLD insulation, with a sharp probe, there's just not that much concern of intrusion of moisture and or corrosion, unless the probed point is UNDER WATER for its remaining life.

Umm, just so you know, there are more than a few automotive technicians specializing in diagnostics in the rust belt area that probably hate you. Even down and away from the rust here, I've seen the green death where people before me have poked into wire insulation. It's extraordinarily bad practice and you better believe it causes problems. The newer the vehicle the more sensitive it is to such wiring intrusions.

All that said, sometimes needs must do. And when you must, at least paint some liquid electrical tape over the vampire bites. It's kind of why the product exists. Some people use nail polish or dabs of RTV silicone. I've found neither actually adhere and seal in the long term on many applications.

Not sure we're "overthinking" this thread but for sure it's wandering all over the road. In a good way though. I think.