Ok to be upfront, I'm no expert electrician by any means, but can manage to work at it long enough to eventually figure it out, but now am looking for a much faster way to go about it is the jest of this thread. Years ago now I bought a used machine, a pretty simple machine really, no computers, all mechanical everything, simple gauges, starter circuit, gauges and instruments are basic at best, but someone has been butchering the wiring harness over the years, cut it apart and spliced different color wires into it, taking things off like sensors and some gauges and basically butchered it so badly, now its time to start over and make a whole new harness, put new sensors on, put new gauges in, it needs a new cab blower motor, the glow plug isn't working, that needs to replaced, simple things. Which brings about the question of the day, whats the best testing tool to use to find out where wires go, where they are dead, where they are shorted together and the largest thing is this, with absolutely no wiring diagram to go by that is accurate. We're finding out the harness has in the past been hacked, patched, rewired, butchered and cut up so badly, nothing matches anything anymore, seems everyone who's come along has used whatever they had at hand to get it fixed, now I have three different colored wires all hooked to one wire throughout the harness, so a red on one end, is supposed to follow through to red on the other end, only its red on one end, turns blue somewhere in the middle and ends up green on the far end................................or changes colors a half dozen times throughout the harness and also changes wire sizes along the way. I know in the right hands, someone could figure this out in a few days, but myself, its taking forever, so the plan thus far is to track the harness one wire at a time, label them with numbers, draw up a wiring diagram, then the plan is to remove the whole harness and make up a new harness that matches a new made up wiring diagram we have to make ourselves with wire numbers already on them and put the whole thing back together again since no harness is available from anyone I can find anywhere, I've spent about a week working off and on and have about 1/4 of the harness tacked down and labeled. We've been so far not trying to make things worse by taking the whole machine apart at one time and some of the harness isn't viable unless we do. I've been looking online and they make short or broken wire testers?? that can track wires through a harness to find a bad spot, never used them, do they work, what is something worth getting that's simple enough any idiot can run, I don't need to test electronic fuel injectors, pulse anything, have graph displays and etc, just needing something basic to help me out, all I've ever used is a multi meter. Thanks for any help in advance.
The Power probe 2 has changed my view on electrical problems. You can hook up to the machine's battery and apply either machine power or machine ground to a wire or unit. It also tells voltage and if wire is grounded or hot. There is no magic involved, still requires quite a bit of head scratching and wire chasing. But is one more tool in the shed to use. Good luck!
Power probe and a digital volt meter is what you need. I usually get by just using a digital meter. But the power probe comes in handy for testing. You can send voltage or ground with it and test continuity ( although I prefer my meter for that.) It's also handy to have a assortment of harness connectors for testing, but that comes from years of collecting. It may not be this way for you, but your project sounds fun to me. I love those types of projects.
You can also by the power probe with a signal generator so that you can scan over the harness looking for a open circuit that is unseen.
You need what is called a time domain reflectometer but they are in no way cheap. They will find wires that are broken from a few inches, to several miles in distance. Best thing to do is get an electrical print of your machine from most likely a service manual and start "ringing" wires from end to end. This means checking for continuity of the conductor(s), (wires). It is about the only inexpensive or affordable way to do this besides visual interpretation. Wire color means nothing to me so point to point measurements are necessary.
Look into a 'Tone Generator'. It sends a signal through the wire that you can follow with the probe and find where wires go even in a loomed harness. I picked up the Fluke Pro3000 model on ebay for $50, but there are plenty of brands and options.
Tone generators are very helpful. I also use a power probe and a DMM with loadpro leads and back probes so I don't have to take apart connections.
This is the broken wire finder/ tracer that I use. $40.00 to your door. Hook the "base" unit up to the wire you want to trace, and the locater will follow along through the loom until the wire is broken, or you can find the good wire at the other end of the machine. The "locater" has a dial which changes sensitivity. https://www.amazon.com/Sperry-Instruments-ET64220-Installers-Must-Have/dp/B00279JLBQ
Just because I'm curious, what are you rewiring? Tile machine? Just trying to get a idea of how many wires and how long to make your new loom. I like the the 3m tape numbers for identifying wires, if you don't have to pull through a swivel. https://www.amazon.com/Wire-Marker-Tape-Dispenser/dp/B00OI737OM?th=1
One of the trenchers is next on the list, that is a one off machine custom built, so there is absolutely no wiring diagram to had for that, since the cab was an aftermarket new cab, then the ac and heat were installed, also aftermarket units, not to mention the engine and laser electronics were never around when the machine was put together, but before we get that deep into that technical of a machine, we're starting out really simple, this unit in the shop now is a feller buncher made overseas back in the 80's and then pretty much discontinued for support anyhow. I have a very vague wiring diagram, or part of one anyway and the rest is just a guess at this point. For as simple as it is, this whole project shouldn't be that hard or time consuming, but minutes turn into hours and hours into days with little to show for my time it seems. I'd cut it all out and start over new, but then I'd have to start from scratch, wire it up and string everything for length, hook it all up, feed it through everything and get it all up to snuff then take it all back out, put it in a wiring harness so to speak, then feed it back through everywhere it needs to be fed through and hook it all back up again. It might get down to that in the end, but I was just trying to piece it all back together first, hook things up and replace the components that need replacing, then take the harness out, lay it out on the shop floor, measure it all up, lay all new wires out to length, mark them all, put it a harness, then feed it through once and hook it all up once was my original thought. This afternoon that whole concept was looking pretty bleak and that idea of just cut it all out and start over was really tempting. I know most of you guys have far more experience with wiring and electronics than I do. Thanks for all the suggestions, one good thing about this whole ordeal, I get to buy some more toys to play with, testers and things, so thanks for the suggestions and information. I now need to study all the things you guys have posted here and figure out how to use them and what will work best for each issue I'm dealing with, heck for that matter, I might just start ordering them all and figure them out as they show up at my door.
I've got a old crane that I keep telling myself that we are going to rewire, because its a cobbled up mess, that I have only added to. I think a guy could get a good start on a system by buying a 21 or 28 circuit system from painless. All the hot rodding guys just install it and it saves a bunch of work. I haven't with the crane, because you have to do it all twice on it, once upstairs and once downstairs, and it all has to go through the swivel too, and I'm just too busy to do it for a old crane. Anyways, the "painless" set up gets you all the typical gauges (water, oil pressure, tach, volts), a ignition set up, and then because its "car" you get turn signals, head lights, wipers, etc. I don't know how much extra controls you need to run electric, but you might just take a look and see if you think you could make something like this work. https://www.painlessperformance.com/wc/20104 https://www.painlessperformance.com/wc/10102 The 21 circuit is only $250 and I could see it saving a bunch of time. I would maybe call their tech support, and see how long the wiring is, and if that would be long enough to work in the feller buncher.
I have the power probe with the signal generator. It works well overall. Other less expensive options have been listed. I have had it not work well but in a large harness with 40 + wires it did not. Cut the insulation off in the middle and then it would read when powered from one end but not the other. Ran one wire from there to the dead side harness connector. Have done a fair amount of that type stuff. Like to start by putting the harness back as original and go from there. If it is real bad, like an old loader that caught on fire with cotton gen trash, cut it out and make your own harness from scratch. Those new high tech machines usually just have to have a harness. Good luck and keep us posted please.
The installation PDF that painless provides with a harness is pretty walk through step by step. https://www.painlessperformance.com/Manuals/10102.pdf
Your doing it like I would have to. One wire at a time and placed on a diagram. My only suggestion, when you are ready to make the new wiring harness, get control cabinet style wire of the gauge appropriate for the load. This wire is very flexible and will take vibration much better than wiring like THHN. I wish I had a brand or wire type to give you. Memory is shot. Maybe Carol wire ( brand and probably not spelled correct ). Good luck.
On one project in the past, we installed a diesel power unit and to wire everything up, we used trailer wire that comes in 7 wires in one coating, when we'd need say 17 wires run, we'd run three of those lines, mark the cables and the wires in each cable then have spare unused wires in each cable for later use. For heavier loads, we'd also run individual larger wires and then zip tie the whole thing together as we went, it did work really good in fact, that machine has been in use now for almost 20 years and we've never had an issue with it. I'm seriously thinking about the same method this time around once we figure out exactly what we're dealing with, and for the larger alternator wire to the starter and dash, just to run a single larger wire and zip tie it to either one or two sets of trailer wires, depending on how many individual wires we need. I had actually forgotten all about that until my wife asked how we wired that up all those years ago...............guess too much stuff in the past to remember it all now. I've been using the wire number stickers like is used in electric motors to number all the wires, once we run out of the numbers, then we doubled them up, say the numbers went to 15 and we'd need more, then a 6 and a 1 sticker to make 16 and so on for each end, I think that's how we did the power unit years ago, the cables were letters then numbers on the individual wires and made up the diagram as we went, once done we photocopied the diagram and then laminated one or two copies and miniature of the diagram and laminated that and taped it inside the cover of the control box so one was with the machine at all times, also made it moisture proof so to speak.
About the ONLY sane method to replace a badly butchered harness is to label EVERY wire END dash or sender then pull the entire mess and build NEW sitting both to a piece of plywood table top. Identify the wires ONE AT A TIME cut them out ONE AT A TIME for a measurement then install a New ONE piece wire with new ends until achieve a full harness. Build your Own Color Coded Diagram as set it up.
I've been pretty lucky in my career to only have had to mess with a couple of burn jobs where the harness has to be repaired as the part number of a new harness could not be verified. It became obvious on those projects that it was easier to just pull the harness out of the machine and do the work on the floor or a bench if possible. There is no good way to piece them back together, they take a ton of time, problems after the repair are still pretty likely if you have electronics and customers whine loudly about the costs. I'm working on a video for harnesses right now and one of my clients donated a butchered cab harness out of a wheel loader. I should have the program finished some time next week. Just a show and tell on this one.
Actually at least for me it's easier to build and install new wiring harness than repair one. It just takes time and patience. I used a EZ harness below and still only used half of it, mainly for the standard items like headlights. The chassis harness I made. Have a plan and work it. When removing a cab harness remove it with switches plugged in makes it a lot easier. I have moved a complete 2005 KW cab harness from one cab to another including power distribution box in 8 hrs.
You guys have far more patience than I posses, as they say everyone is good at something and I for one am good at seeing and appreciating brilliance at its finest. Anybody who could do complex harness removal and installation has my applause any day. While we're on the subject of harness's and much higher tech stuff than I'm dealing with, just who is capable of keeping all this newer stuff running that is sold today, say in 30 years from now?? I was just at a local dealership this week needing repairs for a skid steer, [also wiring and harness related] and while talking to the mechanic this topic came up, so he showed me a bright shiny used tractor, about 2k hours on it he said, the price was 125k and it was currently being bid on by salvage yards, seems the computer system is bad and nobody makes them anymore or can fix them.............so without it, the tractor is useless and being sold for parts I guess is the jest of it. He told me, any machine is just one mouse away from the salvage yard.............took a bit for that to sink in, but he might be right, as he put it, a mouse chewing the wrong wire off could short out the computer and if no computer can be bought to replace it..................to the salvage yard it goes I guess. As he put it, its a David and Goliath world these days, if a mouse can render a 250k piece of machinery useless and basically worthless, what in the world are we doing and where did we go wrong? So as I see what some of you guys can do with complete rewiring jobs, it appears to me your not only under paid, but far under valued for the upcoming future, anyone on here repair computers in equipment, take them apart, fix what's broken and put them back together again, if so, shortly you might be worth more than a surgeon or lawyer and have more work than you'd ever dream of getting.
I made a living keeping 50+ year and older electronic equipment operational; much of it wiring related whether modifications, or repair. Not bad with the proper equipment, but can require an enormous patience tolerance which on the retail level equals $$$. Lot of wrecked cars go total far too easily citing the electronics loading these things have too. Two relatively new New Holland farm tractors in work at the implement dealer I help out are awaiting main engine wiring harnesses. I had to get into one of those and bypass a few thing to trickfu*k the computer to allow it to operate minus a function or three. Almost five months in and no harness yet. I've used a plethora of "Fox & Hound" type affairs, (tone generators) over the years but you simply won't beat a TDR for wire fault tracing whether small signal tracing, or power transmission pathways. The newer ones even distinguish with a visual representation of whether the fault is a high resistance termination, or an open. For the home shop, the tone generator is the way to go IMO.
John C. has made some video's on electrical repair. I have a guy I know who kind of "hobbies" in electrical repair- he repaired a transmission control module box for me by soldering in whatever was bad (I don't know exactly what he did, but it works). I have also sent off a M11 ecm to have it repaired by a guy who specializes in them. I think the internet (forums) and especially Youtube has become a great resource. Any time someone I know has a vehicle problem, I google it and invariably there are two or three videos and numerous posts on the way to fix the problem. Rather than years ago- where you just had to know a guy. It is sometimes difficult to sort through who actually knows what they are talking about in the video's or on forums, but usually that sorts itself out. I tend to fix things out of my own necessity. My equipment, much like the tiling stuff, is specialized, there's few dedicated dealers, and even fewer dedicated mechanics for them. I can't afford new, and I can't afford to have everything worked on by a dealer tech. So I half ass stuff together, by making phone calls, reading on the internet, and beating my head against the wall until it runs right. Because it has to get fixed. I can't afford a $150,000 paperweight in the back yard. I also wonder about the "in 30 years how will this stuff run", when the boards aren't available any more that controls my ZF transmission. There are certain crane LMI systems that are no longer parts available, and there are companies making $12,000 replacement systems, because they are expensive paperweights without the LMI. If there's a need, usually someone will supply it.
It should be that way now. I don't see any difference nowadays. Working on today's machinery is very hard and complicated. It's like being a doctor diagnosing today's machines. Might as well be a lawyer while reading these manuals also. If I weren't so lazy I would rewrite these over the top manuals so that a child can understand it. You also need to be a software geek to work on today's machinery also. I believe I should be getting those three salaries in one. But sadly I don't and never will. In the eyes of the world I am a grease monkey. Not to mention all the parts changers and sorry ass mechanics like the ones in Vetech63 thread. Those guys ruin any chance of a better salary. But as far as a machine becoming obsolete because of computer issues. You can fix anything. It's just a matter of how much you want to spend. One thing that brings me peace is when this world goes to ****. People who work with there hands will be the new leaders and elites.
I've made my living as an electrician 52 years now. I've never replaced a whole harness. On a few restoration jobs, I've made up simple harnesses, IE; antique Jeeps & farm tractors. The very complex modern machines I can't imagine building a harness & last time I priced a complete harness I reconsidered. Best advice I've seen is D Miller's, a big table & the well documented old harness. I might add that some of the old harness may not have to be replaced. The cost of building the whole harness will be high!
One thing not mentioned though, there are ways to properly repair a harness yes. But the more connections, splices bigger the chance down the road for problems. On highway is drenched in salt, fertilizer and de-icing fluids plus being washed with high power degreasing/cleaners. Even harness with the plastic corrugated cover goes to hell, it traps moisture and dirt. Over time it starts working on the insulation then it's green. Wire just tucked inside the black plastic loom is just asking for it, tape it end to end first. Use the correct tools for shrink tube connections and cover those connections with shrink tube, and use dielectric grease. Really 95% of electrical problems that roll into the shop were caused by very poor installation or repair work. If you see a oil leak next to wiring or ecm-----------fix the oil leak.
With the exception of one particularly frustrating Jeep built in 1971, 100% of harness failures were caused by insulation failure, termination failure, or corrosion. Insulation failure is almost always involving friction.
And that is exactly what happens with corrugated plastic loom cover. The vibration from road/engine will wear a spot in the insulation at every dimple. Freightliner is horrible for it, I've found no less than eight to ten wires with little indentations worn through the insulation over a span of 1'. Usually chassis to hood and hood harness. Full of road dirt and water.
Worst mess I ever dealt with was a Flood Carcass. Nice later model truck (Corn Queen) but took a Flood over the Dash on a S2575. Low Miles, owner wanted to fix it back, stripped ENTIRE guts of cab, took cab off frame and power washed EVERYTHING. Harnesses were toast at every end connection but was just old enough IHC no longer inventoried. Dash was a previous model type design and trashed, ended up converted ALL of the dash to Mechanicals, engine was rebuilt and trans fully disassembled then resealed, both diffs punkins and all wheel bearings came down. Spent almost as much remanning the truck as to buying new but kept what he wanted and lasted several years before pockets could not clear mud from rusted thru, got roughly eight years service before began imploding and he sent it to salvage. Not everything is repairable in a financial sense.
True.
Split loom and dirt just turns into a little wire sander over time. Plus the loom we get these days is trash. I like that Tesa tape some of the auto OEMs use way better. I have no problem gutting and starting from scratch, especially if the original wiring is full of bad butt splices and scotchlocks.
Not vehicle, or heavy equipment related. We work on one particular industrial facility where vibration is a constant problem. We used to use metallic liquid tight flex, but found the metal liner wears out THWN copper conductors. We've switched to non metallic, it's smoother inside.
What ever happened to that multiplex stuff International was bracing about a bunch of years ago? One four wire harness line and each component had a processor. Everything was digital and each component communicated through code.
Freightliner uses it.
One of my favorites is finding zip ties securing ABS cables to air hoses that go to brake chambers. Over time the slight flex of the hose under psi swell will break the wires inside ABS cables. That's why those cables are attached to the hoses with special U clips.
Do you have any experience with it? It hasn't seemed to have caught on with any other manufacturers. The concept seems so simple and it would solve a lot of the issues that are happening with wiring harnesses.
Any failures we've had happened under the warranty wire.
Navistar uses it on the 4000/7000 series and the ProStars. It uses a body module or Electronic system controller or ESC and switches that are on a data link to the body module. The data link then goes to remote power modules or RPMs. You can have up to seven RPMs and each RPM has eight outputs and eight inputs. The are also air control units that can have up to seven air solenoids. They are daisy chained on the data link. The biggest problem with the system is usually caused by broken wires. The insulation is soy based and prone to failures.
I agree. Every time someone tinkers with a harness for whatever reason they are shortening its life - and I include using needle probes to prick-test through insulation in that as well. Also I consider that every harness has a working life that will depend to a large extent on the conditions it's exposed to during that life. On the big equipment I've been around when a complete planned component replacement from nose to tail on a machine gets done the whoile thing is re-harnessed after disassembly with brand spanking new ones at the same time. Why would anyone spend a 6 or even 7-figure sum on replacing components and not bother replacing a few of thousand dollars-worth of harnesses at the same time.? IMHO that's plain stupid.
How many wires would you guess are there? Soy based insulation sounds like rodent problems in the future. Is this system programable and can it be updated as you add component systems? Say add a wet kit to a low boy or change trailer configurations somehow? Is it adaptable to older tech like belly dumps, tippers or walking floor trailers?
Last time I was involved in a frame up rebuild the harness change out was well past $10,000 in a big wheel loader. On the retail side, most owners are pretty frugal in that they expect only about half the time out of a second life and then dump the machine before another major rebuild is due. Frame up rebuilds became power train overhauls which reduced the time in the shop and the total capital cost outlay for that time period. I have seen a lot of machines over twenty thousand hours now. Lots of things done to just make the machine run. It's getting harder though to get around the safety systems.
The system programming can be done but its pretty much dealer only. It certainly could be used to run different trailer configurations.
Freightliner also uses SAM.
Ask Tesla owners about Organic based Plastic Insulation, MICE and Rats LOVE those cars!!
Then there is a fire truck. 80% of the wires in the harness are not used, 90% can be removed & scrapped. They literally install hundreds of conductors that have no function, neither end is connected.
Tax preparer had a KIA, 1-1/2 years old. Mice damaged the harness, it destroyed the computer, the car was totaled.