I hate it too, but sometimes you have no choice! Liquid tape will help - for a while! And the rest is the matter of job security
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Warning about power probe!
- Thread starter TVA
- Start date
Nige
Senior Member
Instead of sticking pins in harnesses like a voodoo doll, why not use something like the Cat 7X-1710 Test Probes or the Fluke equivalent..?
They "spoon" slides along the outside of the cable and into any connector until the end touches the pin or socket inside.
I'll post a photo when I find where I put my iPhone cable ...........
They "spoon" slides along the outside of the cable and into any connector until the end touches the pin or socket inside.
I'll post a photo when I find where I put my iPhone cable ...........
I know about spoon probes but on cars sometimes to get to a connector you have to disassemble half of the stupid car! And it might be dead lead! So that’s why they pierce wires.
Nige
Senior Member
All I can say is that our guys aren't allowed needle probes on site - period.
We've had too many wiring harness faults caused by people poking holes in cable insulation and eventual corrosion, even if they attempted to repair the insulation at the time
We've had too many wiring harness faults caused by people poking holes in cable insulation and eventual corrosion, even if they attempted to repair the insulation at the time
Birken Vogt
Charter Member
When back probing, how do you know for sure that the probe is in good contact with the terminal?
At least when you pierce the wire you know your probe is where it actually counts, ON THE WIRE.
I try to limit my piercing to areas where it doesn't matter anyway. Never where water or corrosion could become an issue.
At least when you pierce the wire you know your probe is where it actually counts, ON THE WIRE.
I try to limit my piercing to areas where it doesn't matter anyway. Never where water or corrosion could become an issue.
Nige
Senior Member
Unfortunately with our type of equipment and working in an area that receives somewhere over 4m (160") of rainfall per year on average there are no areas on machine wiring that don't matter. This is especially true of electronic machines that use stabilized ECM-supplied voltage to power sensors and send PWM signals via other wires in the harness. Once dampness gets in you are, in the words of the famous prophet - helically wrapped around an inclined plane. Screwed in other words.
Piercing was done as a standard test method before the current generation of management arrived on site and we are still paying for it more than three years later. Replacing a main chassis harness is a pain timewise, even over and above the $2k price of the replacement.
I made curious observation: around here bulk of wiring problems (mostly excavators) starts around mid spring. When it turns from relitavely dry weather to high humidity and higher temperature.
Another observation is two worst areas for wire damage if a cab and pump compartment, cab I think is a worse, especially where wire penetrate floor or the wall. Maybe if cabs was cleaned more often this wouldn’t happen - but this is a piece of construction equipment, so its not get cleaned as often and combination of dust and moisture creates this muck in which everything gets corroded.
Pump department for some reason almost always covered in oil, and oil over time does the number on insulation, most damage occurs right at connectors, even with weather packs. I blame inferior workmanship and design of wiring on mobile equipment compared to industrial wiring which mostly uses heavy jacketed wiring and DIN solenoid connectors and etc.
Another observation is two worst areas for wire damage if a cab and pump compartment, cab I think is a worse, especially where wire penetrate floor or the wall. Maybe if cabs was cleaned more often this wouldn’t happen - but this is a piece of construction equipment, so its not get cleaned as often and combination of dust and moisture creates this muck in which everything gets corroded.
Pump department for some reason almost always covered in oil, and oil over time does the number on insulation, most damage occurs right at connectors, even with weather packs. I blame inferior workmanship and design of wiring on mobile equipment compared to industrial wiring which mostly uses heavy jacketed wiring and DIN solenoid connectors and etc.
BTW on Tuesday I suppose to replace two multi wire cables on 65, boom lift. The original ones sat under the sun too long, outer jacket has cracked and peeled of and the wire insulation turns to dust as soon as you touch it. The owner decided not to buy derect replacement because hi have big reel of multiwire cable, but the colors will not match, so it will be a lot of fun relabeling everything.
Nige
Senior Member
Our issues on mobile equipment also relate to washing it. Any decent shop pressure washes a machine before maintenance work, but how do you keep water out of places where it shouldn't be while you're washing..? Answer, you can't. The best you can do is to waterproof connectors as best as possible to protect the system during the washing process.
I speak under correction here but I don't think that industrial jacketed wiring would hold up under the vibration of a machine installation.
I’m not sure about vibration but when it comes with better sealing especially at termination points I think industrial type superior.
That’s something I very passionate about! When I see people opening up hydraulic system with all the dirt and dust around the area of work and every move knocks sand clay and dirt down to exposed hose ends and ports because they didn’t care to plug those - I have the urge to induce some physical force to that persons soft tissues, to knock some sence from those tissues to the brain!!!
BTW I spent some money on my plugs and caps, and I use them diligently!!!
I don’t work on other brands too much but Cat is pretty good about wiring quality, routing, and quality connectors. I also usually don’t see too many inaccessible connectors so backprobing is usually not a problem unless it’s just in really tight quarters and I’m not shy about making up a breakout test harness to give access
It irritates me greatly to see shoddy wiring repairs and worksmanship, when doing it the right way usually isn’t hard at all and looks and works much better. It is against company policy to pierce probe, too, for the issues mentioned above.
It irritates me greatly to see shoddy wiring repairs and worksmanship, when doing it the right way usually isn’t hard at all and looks and works much better. It is against company policy to pierce probe, too, for the issues mentioned above.
That’s a thing - a lot of mechanics don’t really regard wiring as important! In instance - they might spend time thinking about best routing, shoring and protecting hydraulic hoses, but they leave wires just hanging, vibrating, rubbing and chafing! I don’t get that, frankly!
May be it’s just Old practice, like before “electric over hydraulic” age?
Talking about good practices: not long ago bought me a wire ferrules kit and crimpers, got tired of constant pull out, frey out and hanging by the single thread issues on set screw types of connections! So if someone still don’t know about these - look it up!
mg2361
Senior Member
I agree with Nige 100% on this one. Wire piercing will do nothing but give you headaches down the road. A good quality back probe set is the ticket.
Great idea!
I never thought of using them. I can see on certain machines how they would help make a better connection (thinking Bomag, Liebherr, etc) where they use screws to secure wires.Back to Power Probe. IMOP, there is no substitute for a good quality DVOM for troubleshooting electrical or computerized circuits. 90% of the problems can be solved with that tool. The other 10%, I personally use either a test light or a Picoscope. All problems can be solved between those 3. PP (2, 3 Hook) and Load pro and the like are OK, I would just rather spend my money somewhere else.
That kit was PP and the tracer. Tracer helps me tremendously, especially finding breaks in the cable of 65/85 manlift booms.
PP, you can do without - but you will spend 4/5 times more time doing the same thing. My favorite use - jumping power to solenoids.
And later I will get The Hook. I even know guys in refrigeration industry who have them and love them.
About multimeters - I have three, good ones, and still thinking about getting low amp very fast updating clamp meter, same reason, to save time, reading change of current on Proportional Solenoids.
And two channel scope, in today’s CAN BUS age you got to have it!
PP, you can do without - but you will spend 4/5 times more time doing the same thing. My favorite use - jumping power to solenoids.
And later I will get The Hook. I even know guys in refrigeration industry who have them and love them.
About multimeters - I have three, good ones, and still thinking about getting low amp very fast updating clamp meter, same reason, to save time, reading change of current on Proportional Solenoids.
And two channel scope, in today’s CAN BUS age you got to have it!
mg2361
Senior Member
I can understand the convenience of testing solenoids with the PP's output. I like the scope for testing solenoids but that would be unrealistic on a man lift (I have not worked on man lifts), so I get that. That is where the extra long leads of a PP could be real useful. I bought the Picoscope 2204A 2 channel and extra long leads, 20:1 attenuator and adapters for my amp clamps ($160 total) instead of the 4 channel automotive ($900). All my research said it would work fine for our application, and so far it has worked great fro me, just be careful of the voltage you are testing (hence the attenuator).
Yeah four channel scope for the hydraulics is an overkill! I don’t even want to do so much electrical work, but in today’s age you can’t get around it.