This tool

[fixkick]

it takes lots of skill to use it.
in a harness, oh boy.
the wires eaCH HAVE capacitance to each other wire,  (do you understand what capacitance does?) and the signals shows up on all wires in a bundle.
so is not very good on bundles of wires, IMO.

but  if you already knew the cable was cut (unseen)
you'd have unwrapped the harness and each wires is laid out  flat separate and the wire with the most load sound is that wire then see if it drops to zero. at cut, hidden deep, in wire.
I have used this VAST Time, and vast ways, homes , businesses and cars  only if desperate and am never.(on cars)

I only need this for in buried deep wires in walls tracking or deep in the ground/
a car never blocks me from gaining access to any wire, ever, and I can test it the normal way. (with any voltmeter)
even using needles is need be.  most times I find the exact section of wire that fails,  like from drivers door to rear of card,  we are talking what here, 5 feet of wire.
then I pull the wire, as I do I see the insulation collapse , BINGO. (mind you the connectors at both ends were inspected and tested for good.)

btw NOTHING NEW HERE,  only FB goons think it is.

Thanks for this. Just curious!

May be you can teach the basics how to find the opened wire or shot.

do you know how say water valve works,  or ever take physics classes?
the first rule of teaching is , knowing  audience skill  underpinnings.
example if you find 100psi WATer pressure at the curb, (street) and zero at in the home, what would you do?
the answer is find a leak or in find  a crushed pipe or , other unknown valve in that line failing clogged or shut off.

electrics works in similar   way.
But the water is now electrons.
WATER pressure PSI or (BAR metric) is now volts.
water flow is now amperes , or amps for sure.  (yes water has flow meter too.  at the curb.  and your water bill is based on that curb meter)

the big difference is electrons don't just fall and leak out a wire like water does (unless doing Tesla 1,000,000  things called HV, for example spark can leak out of spark wires)
A pinched pipe is like cut  wire. water can not flow and neither can electrons...

the way to learn electrics is to practice or use  online testing. (graphics) this is today now and endless topic of choices. learning, there is no lack of free tools or information at all.

Example #1 (and super common)
If say the  brake lamps fails, both)  we use a voltmeter, (any) and measure the voltage at each node alone the way,  from front of car to tail lamp bulbs.
the person A steps on the brake pedal, and person B does this.: (this repeats at every check)

Person B,  grounds the black meter lead to metal body of car, (or neg battery post) meter set to 20vdc range or AUTO. (for all tests)

then touches the RED meter lead tip , to the 1st test point, we will do many. test points.
The order of testing is from easy to reach and then harder.
Remove the left rear tail lamp lens and assemble, screws simple. gate open.


The first point is at the rear of car is on the LAMP brake pin,  if not 12vdc, braked pedal pushed the wiring is bad. if 12vdc is present the lamp is bad, if the ground on the lamp is 0v.
The brake lamp feed lands on left side car first then over the the right so if the feed is bad,(or shorted) both sides fail.

If the line wiring is bad, 0vdc, or say 6vdc  the later is huge resistance in the the line. or the tail lamp is sorted, lamps do short of twisted too hard.
if you remove the left lamp and the right lamp works then the left lamp was shorted. (they (bulb) short is the base brass ring is loose, is it?)

Say the  line is 0vdc, so you move the meter RED test lead, step by step from where you are now to each connector along the way to the dash board of car.

This car wire  lines are a harness, and goes down the left side of car and under the the drivers door sill plate and up the left foot kick panel front of seat.
Alone the way are many connectors, 3 maybe or more, we test for 12vdc at each one, (connectors love to fail on suzuki ,)
lets say the connector  near the driver door shows 12vdc. (front end)

now you know for a fact the wire is cut (or rusty pins) is failing from this point to the rear. (nodal analysis tells you this, using your tests)
learn how to back probe connectors, one more skill, is to use a needle or buy probes with them built in. (or use leather sewing needles to probe)

I then first make sure this connector is not failing,  (the connector has 2 ends (sides) if one is 12vdc and the other is 0vcd the connector bad,  I open it and look omg , gee, its green.
green means corrosion here.  when the pins are sanded the plating is destroyed and the pins then rusts for ever. unstoppable. be that IRon Oxide or copper(brass) Oxide.
the OXIDE FORMATION is an  INSULATOR. and is a hopeless case now. once damaged they CAN not self heal like humans/plants do. we replace them.

I replace all connectors I find bad.  (suzuki connectors suck) I use top brands that are gold plated pins and o-ring sealed. and will never fail.
Lets say the connector is ok both ends. so now we know the failure is to the rear of that connector, and I use my eyes to examine the wire very closely looking for damage.
most times you will see damage, mostly causes by humans hitting the cable doing who knows what.
the wires (alone) just don't go bad , sitting there, ever.  they need help to fail. (humans or collisions )

now we get to the rear tail light well and we see the last owner had  trailer hitch installed, and the guy that did this is  HACK, it's done all wrong and fails. (even lame twisting of wires and black electricians tape used, ALL WRONG. ) bingo ..... I use only soldering and heatshrink tubing repairs. (never butt splice crimped connectors, that will fail soon)

related topics,
how to find cause of blown fuses (not underfused)
https://fixkick.com/power-elect/blows-fuse.html

and this page(huge)
https://fixkick.com/Elect-fail-index.html
 
 dmm page
https://fixkick.com/power-elect/DMM.html





electrons flow  from copper atom to atom, they jump. (physics class covers this first)
if you block that flow , the current falls or ends.  Tail lamps or sensors, you name it , and it ends.

my friends of old called this electron pushing or we the pushers.

good luck.



PS
water proof connectors (again do not think Im telling you any store to use!, ever, this is to show you , new connectors are sold that are good and last.

https://www.ebay.com/sch/i.html?_odkw=wa...&_from=R40


Not carefully these connectors are 2 way,water sealed, something SUZUKI does not understand in 1998 , amazing at it may be.
for sure near the fuel tank, cheap connectors HAVE no place nor under car, under hood or near tail lamps. etc.
inside of a car , there is no water but there is dust. dust too is bad.