Electrical issues

[kp100]

I bought a 1995 Kobelco SK60 last fall. The service screen was showing a wrench symbol indicating a problem. After researching the problem and unable to find a short or blown fuse we changed the control module and bingo the monitoring screen show normal functions. Put 20 hours on the machine last fall and put it away for the winter. Started it yesterday for the first time and the wrench symbol is displayed again. After checking for low voltage from sitting and numerous starts and stops all of a sudden the monitor showed normal function again. Shut the machine down and then restarted it and once again the service wrench appears and no matter what it will not go away. Outside of going through the tedious task of looking for a ground short again in the wiring does anyone have a suggestion for these machines? Is it possible the used control module I bought has gone bad already?
Thanks

 

[NCWayne]

No clue what your particular problem might be. That said having worked on a variety of different brands all I can say is this. When it comes to the electronic system/systems on any piece of equipment nowdays acting up, good luck figuring out what's actually wrong....even if it flashes neon lights telling you what it 'thinks' is wrong. I've had machines flash a code, ran the various troubleshooting flow charts on the machines, had them that tell me the computer is bad. So I spend alot of the customers dollars, change the computer, and then have the new computer start flashing different codes that, once again, troubleshoot out to the brand new computer being bad.

But, hey, changing parts is the new way of figuring out what's wrong with a machine. Even the service manuals nowdays often tell you to replace the suspected bad part with a 'known good' part and see if the problem is solved.

In your case it's probably a bad ground somewhere causing an intermittent problem, but that's just a wild a$$ guess. My best suggestion would be to get a service manual that will tell you how to go into the computer through the monitor, and see exactly what trouble code is causing the 'wrench' to show up. Since it's not showing all the time it should show up as an inactive code when the wrench icon is off and an active code when it's on. GOOD LUCK.

 

[kp100]

Wayne
Thanks for the reply. Question. Do you think a ground short would fry the computer or should not it blow the 5 amp fuse first?

 

[BCnT]

a loose/corroded ground isnt the same as a direct short...highly unlikely it would blow fuse but will raise he!! with electronics...since the problem showed up after sitting all winter i would be checking connections throughout machine first.

 

[tusky]

Kobelco excavators will show the wrench symbol when its time for PM service.

Once you service the unit you clear the code from the ECM and the symbol goes away until the next 250 hr PM is required.

You sure thats not whats happening with your unit?

 

[tusky]

Your used ECM could have been 20 hours away from the 250 Hr trigger point.

just thinking out loud here

 

[kp100]

No one ever mentioned a service interval setting. How do you reset that? I have no book with the machine.
Thanks

 

[NCWayne]

BCnT is right, I'm not necessarily talkign about a direct short to ground, but rather a bad/corroded/etc ground connection. So many systems nowdays work just the opposite of the way things did years back in that they make and break the ground, rather than the hot leg, to operate the components. Because of that a "bad" ground can cause the whole system to go haywire.

That said one of the other posts suggested that the wrench was probably a maintenance issue and to be honest I hadn't thought about that. Typically a wrench is the universal sign for anything maintenance related so that could very well be the answer to your problem.