Case SV340B Intermittent Control Lockout, No Codes
Fault Codes & Symptoms
Intermittent loss of all machine controls (lift, tilt, travel). Related symptoms: - Hydraulic controls not working. - Travel controls not working. - Parking brake will not release. Operator reports that all controls will suddenly stop working. Sometimes it happens when hitting a bump. Cycling the key and lap bar sometimes restores function.
Confirmed cause: Seat switch wiring harness was improperly routed and pinched between the seat base and the frame, causing an intermittent short. Repair performed: The damaged section of the harness was cut out and repaired using solder and heat-shrink butt connectors. The harness was then properly routed and secured away from any pinch points using new zip ties. Verification: The bypass jumper was removed. The machine was operated for an extended period over rough terrain. The intermittent control lockout did not return. All safety interlocks functioned correctly when tested. Technician notes: - This is a good reminder to always check harness routing after any repair or component removal. - The fault was intermittent and would only occur when the operator hit a bump, causing the seat to move just enough for the pinched wire to ground out.