Opinion on tools or techniques to find shorted wiring

Nicholes Technician Pennsylvania Posted   Latest  

So lately I been finding some wires shorted to power in a harness and a lot of them are incased so you can’t really see any rub spot. So I was looking to see what others are doing to find shorted wiring in a harness easier with out having to some times remove the harness and fully inspect it. 

0
Warren Owner/Technician
Virginia
Warren
 

Maybe someone out there knows an easier way, but its cut and trace for me. I follow the affected circuit in sections. If a circuit is shorted, I cut the wire every few feet so i can concentrate on one section. Just need to make sure you repair the cuts properly so that doesn't become a problem later on down the road. I use the crimp connectors you heat and seal, never had any issue's with them.

0
Ð Awarded
Marti Owner/Technician
Michigan
Marti
 

If by chance its shorted to Power/Ground and blowing a fuse(or have a current draw), Ive often found a Thermal Imager to be Extremely helpful.

+1
Ð Awarded
Agree
Nicholes Technician
Pennsylvania
Nicholes
 

No I been dealing with a battery power wire shorted to a ignition power wire. So all it causes them to stay running when the Keys off. And I can normally …rrow down with in a few feet of it but some times touching the harness causes it not to be shorted any more and so the whole harness then needs to come out for inspection .

0
Ð Awarded
Scott Owner
California
Scott
 

Hi Nicholes, How I would approach this would be to look at which wire(s)/circuits are getting power that should not be. First thing a very close inspection of the area where the fault could be. Any new parts, any repairs done, the harness retaped, leaks?... At this stage I'm very careful to try and not touch a thing. If you've ever …d anything and violently moved the harness, now all of a…

0
Ð Awarded
Charles Technician
California
Charles
 

Once you identify the problem circuit running an overlay is an acceptable repair for most manufacturers.

+2
Ð Awarded
Agree
Chris Technical Support Specialist
New York
Chris
 

The problem with overlaying wiring for a short is what about the wire next to the one that was shorted? When not if.

+2
Ð Awarded
Agree
Robert Owner/Technician
Massachusetts
Robert
 

an overlay is a good repair and the wire left in the harness is cut on both ends so it is effectively an open circuit, when cars get a little older it can be ill advised to manhandle harness to remove or locate bad wires, many times you get it all back together and have communication or other faults that were not previously there, don't get too intrusive with a harness, this is coming from a guy…

0
Ð Awarded
William Technician
West Virginia
William
   

Running a new wire is the easy way out. Not a good option if you are interested in root cause diagnosis, but I admit it is sometimes needed if the harness is inaccessible or poor harness condition.

+2
Ð Awarded
Agree
Louis Owner/Technician
New York
Louis
 

Charles, an overlay is never acceptable for a shorted wire. Cut the shorted wire and then run a new conduit. Louie

0
Ð Awarded
Chris Technical Support Specialist
New York
Chris
 

I like to place a Halogen light bulb in place of the fuse. With a low current draw, the light may glow slightly dim. A short or high current command will light the bulb brightly. I have my lamp connected to about 12 Ft of wire and used it for load testing and also for short finding. Disconnect inline connectors until the light goes back to dim or watch the light and wiggle the harness from one…

+1
Ð Awarded
Agree
John Manager
Indiana
John
 

We use the Power Probe kit with the short open finder it work fairly well. Old school is to use an auto-reset circuit breaker and a compass, the compass will change at the short.

+3
Ð Awarded
Agree
Nicholes Technician
Pennsylvania
Nicholes
 

I have a power probe short finder but I’m not sure how I would use it to find a igntion power wire shorted to a battery power wired.

0
Ð Awarded
John Manager
Indiana
John
 

Is the ignition wire actually hot all the time? Or is it a code saying shorted to power or open circuit. Can you pull the ignition relay or fuse and still have power on the line. Is there anything on that ignition circuit that can back feed power? Bad grounds can cause weird issues.

0
Ð Awarded
Dave Owner/Technician
Oklahoma
Dave
 

How about a signal tracer? I see a fault finder ff300 on fleabay for 50 bucks right now.. … is the item number. Mine works really well..

0
Ð Awarded
Tony Owner/Technician
Missouri
Tony
   

I don't know all of the details but if you can pull the fuse that powers the circuit that is “staying hot when it shouldn't” and the circuit is still hot, I'd try adding a significant load on the power wire of this circuit (match it to the fuse for safety of the wiring), then test voltage drop across each B+ fuse on the vehicle. Your test load should be by far the largest consumer key-off so the…

0
Ð Awarded
Kevin Owner
North Carolina
Kevin
 

If you can access the fuse in one of the circuits that is causing a problem we have a new tool that may help you with troubleshooting. This tool simply watches for a change in the circuit and alerts you when the change occurs. All you have to do is the standard wiggle test. When you get to the location of the trouble, the tool will beep to let you know there has been a change in the circuit…

+3
Ð Awarded
Interesting
Michael Technician
Indiana
Michael
 

Kevin , Let me know when your new tool is available and price. I would like to try also. Thanks

0
Ð Awarded
Kevin Owner
North Carolina
Kevin
 

Hey Michael, hopefully it will be available later this year through Lisle and the cost will be less than $100. BTW, I should have mentioned that since it only senses a “change” it works great for opens, intermittents and any sort of flaky wiring, ground or power connection too. Wiggle testing is a quick way to scare up a wiring or connection problem.

+1
Ð Awarded
Thanks
Kevin Owner
North Carolina
Kevin
 

Hey Michael, I happened to remember that I made a video a couple of months ago for this tool. Let me know if you think this would help you with troubleshooting. youtu​.​be/CSzThJcaidA Thanks, Kevin.

0
Ð Awarded
Glenn Owner/Technician
Texas
Glenn
 

Hi Kevin, Did you make that or buy it? It is more compact than what I use. I am interested.

0
Ð Awarded
Kevin Owner
North Carolina
Kevin
 

Hello Glenn, This is something that I made. It is covered in-part by an earlier patent of mine and is pending a separate patent now. What is it that you use now? Thanks, Kevin

0
Ð Awarded
Glenn Owner/Technician
Texas
Glenn
 

Hello Kevin, I use an older MAC tool, fault finder among others like a power probe. I did cobble together an old door buzzer with an inline circuit breaker. I use it when dealing with issues far away from the fuse box. Over the years I have collected a tote box of electrical circuit testing tools, most of them were made on the fly while chasing unique circuit issues.

0
Ð Awarded
Paul Mechanic
Illinois
Paul
 

Regardless of a short, open or draw, I like to cut the circuit in half figuratively between power/ground and load. I check schematics and find all the connectors in between. Then access the easiest to get to and disconnect to see which way to go next. Limits unessarily pulling interior components. I also agree with Chris about overlays. You may be missing something that could be building that…

0
Ð Awarded
Juan Diagnostician
District of Columbia
Juan
 

I usually take power off from the circuit that has a problem(remove fuse/disconnect connector). The I check when do I get power to that circuit. Is it during key ignition On? Key Start position? Key Accessory mode? Key in any position? Once I know in what position does the key need to be to power the circuit. I take a moment and start thinking what other circuits power up on that specific key…

0
Ð Awarded
Glenn Owner/Technician
Texas
Glenn
 

Hi Nicholes, A large paper clip and feel for any wires getting hot…??? That was actually a test method a body shop was using at one of the companies I worked at. Needless to say, I was the guy in the mechanic shop who usually had to pull the full harness out of a dash and repair the damage. A screw driver in the back pocket and a vehicle with heated seats do not mix. I was using my Superman…

-1
Ð Awarded
Dangerous