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Discussion Starter · #1 ·
Had a fuse blow the other day that powers some sensors including rotor speed, spreader speed, feeder speed, water in fuel sensor, and a couple other sensors. This happened once before so that indicates damage to wires in the harness, but a new fuse held, so I thought I was okay, at least for a while.I put in a new 10 amp fuse while the key was on (which may have been stupid), and it promptly blew out. I turned everything off and put in another 10 amp fuse and when I turned the key on it did not blow. However when I started the engine, the rotor began to turn. That's very bad. Got a Rotor EtR Current Sense Shorted error. The 12V orange sensor wire was shorted to one of the Rotor EtR solenoid wires. Long story longer, after fixing up the wiring harness and following the diagnostic procedure for the error message I determined that the computer itself was faulty. I even ran two two wires from the underside of the cab back to the Rotor EtR solenoid and still no change. I determined the computer wasn't even sending volts to the solenoid, although the current sense side of the circuit still worked. Service tech came to the same conclusion and we stole a computer out of a combine in their shop and confirmed what we suspected. So I have a replacement CCM computer module on order. @lanwickum said a few years ago he'd only changed just a few computers in his entire career. I guess I must be bad luck. Hopefully with the wiring harness fixed up, and some new wires run, we can avoid this particular problem in the future.

If I had more time I'd probably try to find a computer out of a wrecked combine somewhere.

Now for the right to repair stuff. I cracked open the computer box and sure enough, something on the board had exploded. The remains were too melted to be identifiable but I suspect it was a power transistor of some kind. The area that leaked the magic smoke is not densely populated and despite the board being multi-layered I strongly suspect boding some burned traces and replacing a few components would fix this computer. If Case provided just a schematic, this could be repaired and returned to service quickly. Instead they'll give me a core refund on the burned out computer, which they might fix, or just toss.

By the way I removed all the ribbed plastic sheathing from several feet of harness around the rotor and feeder solenoids. Lots of wire damage. I recommend anyway pre-emptively strip all those sheathings off and just tape it up with cloth or electrical tape. The smaller bundles get damaged the most from what I can see. You can pop off the joints and then the sheathing removes quite easily. this winter I'll go over it more thoroughly.
 

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That stinks, literally. Don't the smoke of those things. It needs to stay inside!!

I went through 3 bad PCU on a Ford escape I bought with a bad PCU for cheap. They kept sending me bad ones that were supposed to be rebuilt. Finally had to buy one from a junkyard. It now runs great. Somedays just don't go your way. Hope they had one available to get you going quick.
 

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Those look like reverse current protection diodes that blew. It's common on X20 monitors and Deere CCUs....


$0.75 part. I bet it never blew a trace, from the looks of it. just had a short somewhere that overloaded it?


Not having diagrams is my biggest complaint. Especially now that one of the big manufacturers of all these boards disappeared in merger, and all the old stuff got obsoleted (name starts with a "V").
 

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Those look like reverse current protection diodes that blew. It's common on X20 monitors and Deere CCUs....


$0.75 part. I bet it never blew a trace, from the looks of it. just had a short somewhere that overloaded it?


Not having diagrams is my biggest complaint. Especially now that one of the big manufacturers of all these boards disappeared in merger, and all the old stuff got obsoleted (name starts with a "V").
Vansco?? dang I hope not!! They made a LOT of OEM monitors and control boxes!
 

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What is the nature of the damage to the wires in the loom? Are you thinking the wires are rubbing together from movement of the harness and so grinding off the insulation? I always considered the loom as a means to make tidy wire runs and protect the wires from external damage. Internal damage should not be occurring as the wires themselves should have durable insulation. Though that may be the issue right there.

I assume you are talking split loom/slit loom - that plastic stuff with the ribs running around the outside and a slit down the middle.
 

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Discussion Starter · #8 ·
Yes the plastic split loom stuff is the problem. It's not the wires rubbing together that's the problem. It's actually abrasion of the plastic ribs of the split loom sheathing against the wires. I'll post a picture later today. I expect all CNH combines to have this sort of damage in their looms after some years. I think it's likely to break wires before you'll see a short. I was just unlucky to have that 12V power wire short with one of the rotor EtR clutch solenoid wires.

I'm sure it would have cost CNH more money but braided looms would not have this abrasion problem.
 

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Discussion Starter · #9 ·
even more annoying when the component is marked as a resistor [R10?], the simplest and cheapest part of all...
Picture wasn't very clear but there are three big pads under the burned out area if I'm not mistaken. I'm sort of tempted to take one of the other computers apart and see what that component is. But I think I'll let this one go. Maybe if there was no replacement available I might consider doing that. The unit itself is otherwise functioning. It can read voltages from various sensors just fine, and responds on the bus. It's just the 12V output(s?) that is dead.

Dealer let me use a loaner module they took off a combine they've got in the shop for a few days. Hopefully by then either I'll be done or the new module will have arrived.
 

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Discussion Starter · #10 ·
Vansco?? dang I hope not!! They made a LOT of OEM monitors and control boxes!
Indeed that is bad news! Pretty much all sensors on my air drill are made by Vansco. Guess I better start hoarding parts like the acoustic level sensors. Worst case I tear it all out and replace it with Raven I guess. Or some day maybe AgOpenGPS and a custom rate controller.
 

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Vansco?? dang I hope not!! They made a LOT of OEM monitors and control boxes!

Yep. Vansco was bought out by Parker. And... pretty much instantly all the old stuff has been obsoleted.


I'm sourcing a bunch of compatible sensors for them as I doubt there will be many places that will stock them going forward.
 

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I don't doubt you are right Torriem about the loom wearing on the wires. Visual damage can only be caused by so many things. But that doesn't bode well for the quality of the wire. I would never of suspected it is possible for a loom, whose job is to protect the wire from abrasion, is the item that is doing the abraison. Those loom sleeves aren't that bad. So what it means is the wire itself is that bad. Wire is made for many different applications and naturally durability of the insulation is the thing that changes. Copper wire is copper wire, what is put on it is what determines how it functions long term. If wire loom is rubbing off the insulation it tells me Case really made a big oops to use a wire whose insulation can be so easily worn off.
When shopping for automotive (or any kind of wire really) there are many different options. And they get more expensive but durability for mobile equipment does rank up there pretty high as a factor to consider rather than just $$. Xlpe insulation is noticeably tougher than pvc, you can tell right away when you strip it. Xple is usually the dull colored/pastel insulation, if it is glossy in color it is usually best to avoid that wire for use where durability matters.

This link touches a bit on the different insulation classes for auto wire. I am going to bet the wiring you have isn't of a very durable insulation design.

 

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Torriem I have a few old ccm’s laying around I don’t know where they came from they have been in the shop longer than I have. If you travel south of the boarder I would probably let one go if you wanted to tear into it. The sensors for the drills is a huge problem, there are no fan speed or meter speed sensors available anymore. The fan speed likely would not be that hard to get another sensor to work on. The meter speed I’m more worried about because of the shape it needs to fit. If anyone knows any substitutes off hand let’s hear it.
 

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The problem with the Case wiring harnesses is they had the bright idea to zip tie the loom to the steel hydraulic lines. Nylon seems to always win so after 1000-1500 hrs of vibration the wires are cut by the loom and shorting together. I can’t remember what coming they went to cloth loom but it was either the 30 series or 40 series that helped a ton.
 

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Hard to believe KenMB but the flagship wiring is famously notorious for internal rubbing in the plastic sheath.
This pic is down on the front axle on top off the gearbox. There’s no harmonic vibrations here like the PTO gearcase hyd lines. The gearbox usually has a pile of chaff, dust and grain on it so there’s no better cushion than that. Yet they still rub themselves to death. Puzzling
 

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Using wire loom like that is not made for vibration what so ever. Case should have their head examined or any other manufacture for that matter that uses wire loom like this in anything with vibration The cloth stuff has always been trouble free for me for decades on old Gleaners. The wiring Gleaners had yrs ago was superior. I can't say anything about the S series because I have never owned one but this shows what to look for when considering a combine. You just don't usually consider a wire harness giving trouble. These days fire it out the door for cheap as possible and sell for the most you can is the new normal. With everything electronic the future of how wiring is done on a machine will determine it's life expectancy. That board is likely made in China for $2. You won't buy it for that though lol. My Polaris Ranger had all the wires from the cab run through a clamp behind the cab with that loom. 18,000 km it looked just like your wires.
 
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