What was found
DURING TAXI ,ELEVATOR FEEL / STAB TRIM EICAS APPEARED. AC RETURNED TO GATE AND MAINTENANCE GROUNDED AC. WHILE PERFORMING T/S WITH MCC FOUND PRESS SWITCH LEFT FAULTING ON SPM UNIT REPLACED SWITCH PER AMM 29-11-18. ALSO FOUND L HYD PUMP WITHOUT PRESSURE + WITHOUT L "SYS PRESS" LIGHT OR LOW "PRESS" LIGHT ILLUMINATES. NO HELP ON ORIGINAL ISSUE. T/S CONTINUES. CHECKED WIRES AT HYD PUMP REF WDM 29-11-12 + NO CONTINUITY FORUND ON PIN 2 OF UPPER HEAR SENSOR. NO POWER FOUND ON A/C CONNECTOR. T/S L HYD PUMP FLCU REF WDM 29-11-12, SSM 29-00-02, FOUND NO OUTPUT HOUR AT ELFU PER AMM 29-11-14. NO HELP, REINSTALLED ORIGINAL ELCU. T/S CONTINUES. SUSPECT PUMP AT FAULT. REPLACED L HYD DEMAND PUMP PER AMM 29-11-01, NO HELP. TRACED WIRE FROM OVERHEAT CANNON PLUG (D916) , FOUND LOOSE CANNON PLUG (D42808) TIGHTENED PLUG AND OPS CHECKED PER AMM 24-41-00 + AMM 27-31-00. STATUS MESSAGES CLEAR, OPS CHECKS NORMAL. NO FURTHER FAULTS AT THIS TIME.AC IS RETURNED TO SERVICE