Doosan DX225LC-5 Gauges Fluctuate, Erratic Operation When Swinging
Fault Codes & Symptoms
Gauges and monitor flicker or sweep, controls may become erratic. Related symptoms: - Unexplained or intermittent fault codes. - Erratic hydraulic control response. - Control joysticks (EH) may become unresponsive temporarily. - Engine may stumble or lose power momentarily. The operator reports that when he swings the excavator, the gauges on the main monitor all sweep to zero and then come back, and sometimes the machine feels like it loses power for a second. It seems to be getting worse.
Confirmed cause: The main chassis ground cable was chafed through at the point it passed through the carbody frame near the rotary manifold. The constant friction from swing operations had worn through the insulation, causing an intermittent and poor ground connection for the entire upper structure. Repair performed: Repaired the damaged section of the main ground cable using an approved sealed splice connector. Re-routed the harness slightly and installed a new protective grommet and extra conduit to prevent future chafing against the frame. Secured the harness to prevent excessive movement. Verification: Operated the machine through all functions, with special attention to rapid and repeated swing operations left and right. The gauges and monitor remained stable with no flickering or resetting. All controls operated normally. The repair was confirmed successful. Technician notes: - This type of chafing failure is common on machines with high hours, especially if they do a lot of repetitive loading cycles. - When diagnosing electrical issues that are related to movement (swing, articulation, boom/stick movement), always inspect the harnesses that cross the moving joint first. - A simple voltage drop test under load is often much faster for finding a bad ground than a resistance check on a static machine.