Description

PAT DS 350GM, RT875CC 2002 Service Manual

You’re staring at a lever lockout on a Grove RT875CC, and the aftermarket paper you bought off eBay has a wiring diagram that looks like it was photocopied three times and then run through a scanner from a fax. I’ve seen it. Wasted billable hours because someone thought a generic manual would cover a crane’s load moment indicator. This is the real factory book: PAT DS 350GM, RT875CC 2002 Service Manual, Original OEM print from PAT America, P/N 031-300-190-155. 56 pages of what you actually need.

Flowchart Navigation: Error Codes and Lever Lockouts

Section 3 of this manual is the part you’ll live in. It kicks off with a general flowchart on page 3, then dives into specific error code displays (page 4), lever lockout (page 14), broken length cable (page 15), no display (page 16), anti-two block (page 18), length reading problem (page 21), angle reading problem (page 24), and the load reading problem on page 26. Each one is a decision tree. You start at the top, follow the yes/no questions, and it spits out which wire to check or which sensor to replace. No guesswork. No flipping between five sections hoping something lines up.

Does This Manual Cover the Load Reading Problem?

Yes. Section 3.9 is titled “LOAD READING PROBLEM” and it walks through the pressure transducer zero adjustment procedure in Procedure 4 (page 45). It tells you how to use the graphic console for zero-setting of pressure transducer and force inputs. If you’re getting bogus load numbers on the console, that’s where you start. The theory sections (Section 6) explain the piston side and rod side load sensor operation so you understand why the reading is off before you touch anything.

3 Critical Wiring Drawings You’ll Use

Drawings 1, 2, and 3 (pages 30–32) are the electrical wiring diagrams for the central unit to pressure transducers and crane, central unit to console, and central unit to cable reel / anti-two block. These are not generic schematics—they’re specific to the DS 350GM installed on the RT875CC. Each drawing includes connector pin numbers, wire colors, and the ground paths. If you’re diagnosing a bad data transfer between console and central unit (Section 3.10), you need these drawings.

EPROM Installation: Don’t Skip the Procedure

Procedure 2 on page 43 covers EPROM location and installation. This is the part where a lot of guys think they can just pop the chip in and go. Wrong. The manual specifies the orientation, the handling precautions to avoid static damage, and a verification step after installation. Miss that step and you can lock yourself out of the console. I’ve seen it. Follow the page exactly. If you need additional documentation for related PAT systems, check the PAT DS150C DS 150 2002 Service Manual or the PAT DS 350G DS 350GW Service Manual for similar models.

Get the Right Calibration Data

Procedure 5 (page 46) is length and angle sensor adjustment. Procedure 4 (page 45) is pressure transducer zero adjustment. Both require the OEM values that are printed in this manual only. Not in a third-party reprint. Not in a PDF that was scanned at 72 dpi. The theory sections (Section 6) break down the operation of the boom length sensor, piston side load sensor, rod side load sensor, and angle sensor so you understand the physics behind the calibration. There’s even an anti-two block theory that explains the switch logic. If you’re running a fleet of cranes, you’ll want the PAT DS 350 IFLEX5 2003 Service Manual as well.

Why OEM Documentation Matters for Safety

The warnings section (Section 2) is two pages of safety information that covers lockout/tagout, electrical shock hazards, and the consequences of using the wrong load limits. PAT’s legal notice on page 3 states they are not liable for incidental or consequential damages from using the manual improperly. That means if you use an aftermarket copy that has a typo in a torque specification, you own the resulting failure. This manual is the one the factory techs used. Don’t trust something that came from a file-sharing site.

For context on how a manual transmission differs from a load moment indicator’s components, see Manual Transmission. And if you’re comparing crane control systems to automotive gearboxes, the Manual Transmission analogy ends at the word “manual”.

Does this manual include torque specs for the hydraulic fittings on the RT875CC?

No. This manual covers the load moment indicator electronics and sensors, not the crane’s hydraulic system. Torque specs for the transducer fittings are given in Procedure 4 (page 45) but that’s for the sensor mounting, not the overall hydraulic circuit.

What if I have a DS 350G and not a DS 350GM?

Then you need the DS 350G manual. The DS 350GM variant is specifically for the RT875CC Grove crane with a different console board (Drawing 5A on page 35) and a different central unit analog input module (Drawing 9 on page 41). Don’t assume they’re interchangeable—the wiring pinouts differ. Check the PAT DS 350G DS 350GW Service Manual instead.

This is the original factory document from 2002, 56 pages, published by PAT America. Every flowchart, every drawing, every calibration step matches the DS 350GM system installed on the RT875CC. Access the Factory Manual and keep it in the cab or on the bench. You’ll use it more than you expect.