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Case 621E

Tony Wells

Senior Member
Joined
Jul 18, 2019
Messages
635
Location
Tyler, TX
Occupation
HogZilla Keeper
Got called in today on this one. Ride control issues. Blows fuses instantly. Not entirely sure I understand the system but the machine doesn’t want to function even with it switched off at this point.

Any tips to explain the methodology of this system would be appreciated.

A schematic would be wonderful!

SN is N7F202824

Thanks for any help
 
Last edited:

gggraham

Senior Member
Joined
Feb 13, 2009
Messages
588
Location
London Ontario Canada
Occupation
Licensed Heavy Duty Equipment Mechanic
Schematic, sorry for the format. Cannot break out the page from the PDF File. Complete file was over 155mb. So here it is in pictures you can piece together
 

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Tony Wells

Senior Member
Joined
Jul 18, 2019
Messages
635
Location
Tyler, TX
Occupation
HogZilla Keeper
Thank you, Gil. I appreciate the hassle you went through to get those. They will help as I get familiar with the circuit. That function seems to involved more than a few hydraulic controls.

If I might offer a hint, if you have that open in Adobe, you can use the "print to file" (shows up under the Print command, for each page you have open, and select print to "Microsoft XPS Document Writer" or "Print to PDF". In that dialog box you can select individual pages or groups, depending on what you need. That will generate a single file with the desired information. Depending on your Win version and what applications you have installed, the options may vary, but there is generally a way to just clip out a page or two instead of capturing screenshots.

A little more information on the problem. There is a 5 amp fuse in the ride control control circuit and it would invariably pop it as soon as you went key on. Not being familiar with the entire system, only the concept, my helper and I began to umplug various solenoids and what seemed to be sensors, and after just about everything d/c, it still blew. Just happened to look along the LH curl cylinder and there was a loom with nothing on the end....except 3 bare contacts that looked like they had been pulled from a connector. Still crimped on, no connector in sight, and definite signs of arcing. We searched in vain for some component that was unplugged, mangled, or anything that looked like it might mate with the three wires. Nothing. Not even any suspicious mounting points for anything. Kind of got the feeling that whatever it was connected to has been removed and the connector was left to dangle, and finally got tangled up enough to shuck the connector exposing the wires.

So in an experimental mood, I separated those three wires and the fuse stopped blowing. So for now, until I can get a service manual and see what is supposed to be there, those three wires are shrink tubing protected and coiled back safe. Everything seems normal now, although I can't believe that to be true with a component missing. But it does run and the hydraulics are enabled so they will use it until I get a manual.
 
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