Technician requires some insight ( Energized frame w/ batts off )

[TEX32]

heymccall: I am unsure of what you are calling the `product link` fuse. I have in fact pulled fuses, systematically in an attempt to locate the problem circuit, to no avail. ( Same as diagnosing ghost draws )

kith: This particular machine does not have an additional `keep alive` wire. Straight forward, two post switch.

 

[Nige]

I don’t think a 980G (2KR I imagine) is new enough to have Product Link installed, unless someone’s done a retrofit somewhere.

 

[Ronsii]

heymccall: I am unsure of what you are calling the `product link` fuse. I have in fact pulled fuses, systematically in an attempt to locate the problem circuit, to no avail. ( Same as diagnosing ghost draws )

kith: This particular machine does not have an additional `keep alive` wire. Straight forward, two post switch.

LOL, he means the 'smart phone fuse'

even our 94' hitachi ex has the keep alive circuit to protect the computers from rapid on/off spikes, it is designed to keep the power alive for a minute or two after everything is shut down... and is controlled through the alternator to determine if the machine is running so when the alt. goes bad it can cause funny things to happen.

 

[John C.]

Product link wasn't a standard feature for G model wheel loaders. If you find a machine with it, someone paid to install it after the initial sale. Product link is powered down when you open the disconnect on newer machines that I have experience with.

What I might suggest is to unhook the battery wire to the disconnect switch with the light hooked up. I've seen the ground disconnects bleed through when they get old. I'm not familiar with the power probe product so was wondering if it might be a little too sensitive to voltage?

 

[TEX32]

John C.: I do believe we are on a similar thought process, re: Power Probe. However, no matter what type of electrical tool is used to diagnose, it shouldnt `arc` out when touched to the frame ( or when an artificial ground is supplied to frame, that it creates a spark @ initial contact... ) The battery switch is in perfect working order, not shorted internally or shorted to mounting area.

P.S. You totally need to get yourself a Power Probe. Hands down the best money I have ever spent on a tool. Ever. Once you use one, you will NEVER go back to jumper wires, test lights, squirrel nests of wiring, alligator clips, etc...

 

[JPV]

Now you have me curious, can you check any of your other cat machines to see if they do the same thing? I still kind of think it is normal, my guess is you are seeing the power draw that the battery switch is there to cut off but I am probably wrong if past history is any indication! Second the power probe comment, wouldn't be without one.

 

[TEX32]

JPV: Unfortunately, my sister machine has been sent out to a jobsite. However, the battery disconnect indicator LED that I installed on that machine turns on and off perfectly... Frustrating...

 

[JPV]

I see, sounds like you have something going on then, will be watching to see what you come up with, those other guys had some good suggestions.

 

[TEX32]

JPV: ``sounds like you have something going on then``... Truer words have never been spoken. err, typed...

 

[Cmark]

• Disconnect the ground lead from the master switch and remove all four battery negative terminals. The problem SURELY must be gone by now.
• Start reconnecting things one at a time until the problem reoccurs.

That HAS to lead you somewhere.

 

[kshansen]

Tex32,
Probably not the problem on your but many years ago I had a strange electrical problem that I don't recall the details of but just recall finding voltage going some place I didn't expect it to be. What I do recall is the source of this strange "leak" of electricity was a dirty battery!

This was an old Mack truck used off-road in a sand and gravel pit. Between all the moisture and dirt and the fumes inside the battery box putting a touch of acid on top of the battery you could get a volt meter to read a few volts just by touching one lead to the + terminal and the other lead to any place on top of the battery half way between the two terminals!

I could see an accumulation of dirt and corrosion some place on either the disconnect switch or even between one of the battery hold downs and a negative battery terminal causing a "leak" of electricity that was able to get a LED to glow.

Like Cmark says one way to find the source is to disconnect every negative terminal connection and then reconnect each one one at a time to see which one lights the LED. And if the LED lights with all four negative cables off the battery clean around each one till LED goes off!

And please let us know what the solution was, nothing worse that someone getting a problem solved and not letting us know so we can point the next guy with a similar problem to a solution.

 

[Shimmy1]

I nearly got fired for something similar.
We started a new jobsite and I checked each machine as they came off the lowboy (10pcs). Put 10 unit numbers in a hat, and picked one. Taped a $20 bill to the engine oil dipstick on a Caterpillar 330CL. Had other obligations and didn't return to that site for three weeks.
It was an overcast day, light breeze, I'm guessing mid September, about 1pm, and as I drive in, I see the Cat 330 at work.
Tell the operator that I had to get something from under the engine hood. He idles down, I climb up top. As I'm removing the dipstick, a curious operator watches from inside the cab. I nonchalantly unfurl a $20, all the while avoiding any more eye contact. I close the hood, climb down, get in my truck and proceed to the other side of the jobsite.
I heard absolutely zero chatter on the 2way radios or the CB, but, it took 11 minutes for the owner to ring my phone.

Turns out that they were test demoing a new excavator operator that day. To his credit, he did work until end of shift. Was never told if he quit, or was released for underperforming as a ditch digger.

So why did you almost get fired?

 

[John C.]

Another item I might ask is if someone wanted to listen to tunes and hooked up a power lead somewhere to run a voltage drop or they just fed off one battery to run it.

I'll look into the power probe.

 

[TEX32]

Cmark: I did this as well. The energized frame continues, even when all the NEG terminals have been removed. This is what lead me to believe that I had a POS cable or circuit rubbed through somewhere in the machine. Upon checking and rechecking my harnesses, I determined them to be in good working order. As earlier stated, I`ve even pulled all fuses, circuit breakers, bus bars and relays, to systematically isolate any problem component or circuit.

kshansen: I originally did in fact, have a draw or drop across the batteries. Our machines run in a steel plant, and the batteries had kish & coke built up on top of them. I had measured continuity between the POS terminals and the hold downs. This was the 1st item rectified within my electrical gremlin journey. Batteries are now 100% clean and isolated. I even went as far as to remove & inspect the battery cases themselves to eliminate the possibility of them feeding voltage into the batt box.

John C: There a no additional added circuits within the system.

This is fun, eh? **totally Canadian slang right there**

 

[Nige]

This is a voyage of discovery somewhat akin to Columbus discovering the New World.........

OK, so you pulled all the neg cables, still had the issue. then you went on to pull fuses, CBs, etc. Do you have the Electrical Schematic for the machine..? A Serial Number and an email address gets it for you.
Another question. Does it still have a 3406 or has it been re-engined with a C-Series engine at some point..?

The only thing I can possibly think of is that there is +ve power feeding something that does not go directly to the fuse/circuit breaker panel, or that the main 4 SWG power cable from the batteries to the fuse box is leaking power somewhere where it passes through a main connector.

You say it is a steel mill application. Are all your harness connectors sealed with non-conducting tape..? If not then what's the chance of iron dust that has got inside a connector somewhere allowing power to track in weird directions..?

 

[franklin2]

What about a very dirty and corroded battery box and/or a metal battery holddown across the top of the battery picking up some power from the terminals on the battery. A LED takes very very little current to run.

 

[TEX32]

Nige: I do have the electrical schematic ( Thank God ) This engine does have a 3406. I agree with your 2nd paragraph and believe that this should be the area of concern... AND your 3rd is absolutely dynomite !! Honestly never even had this cross my freakin` mind....
Now to inspect. Every. Single. Deutsch, Weather Pak, Terminal and plug. In the. ENTIRE. MACHINE...

 

[TEX32]

franklin2: See previous posts.

 

[Nige]

Nige: I do have the electrical schematic ( Thank God ) This engine does have a 3406. I agree with your 2nd paragraph and believe that this should be the area of concern... AND your 3rd is absolutely dynomite !! Honestly never even had this cross my freakin` mind....
Now to inspect. Every. Single. Deutsch, Weather Pak, Terminal and plug. In the. ENTIRE. MACHINE...

Sometimes even a blind squirrel finds a nut.........

Seriously though, we are in a very wet environment (think 200" of rain a year). We waterproof all our harness connectors with a product called Senson Electroguard grease and waterproofing tape. I did post a copy of a Cat Best Practice document somewhere a while back detailing how to do it.......

 

[Nige]

https://www.heavyequipmentforums.com/threads/cat-287b-high-flow-not-working.72393/#post-769475

Post #13 has the attachment I spoke about.