MD80 MECHS THAT MELED THE APU INOP DID NOT CLOSE AND DEACTIVATE THE APU RAM INLET DOOR CLOSED.

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UPON MY ARR AT THE ACFT IN ZZZ MAINT PERSONNEL WERE BUSY TRYING TO TROUBLESHOOT WHY APU WOULD NOT START AS MECH STATED HE WAS UNABLE TO CORRECT THE PROB AND THAT HE WOULD PASS INFO OF WHAT HE HAD ATTEMPTED/ACCOMPLISHED TO HIS SHIFT SUPVR FOR ACTION WHEN THE PLANE RETURNED FROM THE TURN TO SAT. THE APU CTL CIRCUIT BREAKER WAS PULLED AND COLLARED AND THE ITEM DEFERRED IN THE MAINT LOG. ON APCH TO SAT I NOTED THAT THE ACFT REQUIRED AN INORDINATE AMOUNT OF EXTRA THRUST TO SUSTAIN SPD AND ALT WHEN TURNING TO INTXN ILS FINAL AT SAT. THE SHORT TIME ON THE GND AT SAT MAY HAVE CAUSED THE FO TO MISS THAT THE APU RAM AIR DOOR WAS IN THE OPEN POS. THE CREW CHIEF RPTED THE R NOSE TIRE WAS SCUFFED AND TREADLESS COMPARED TO THE OTHER NOSE TIRE; WHICH ACCOUNTED FOR THE SHIMMY FELT ON DEP AT ZZZ. EQUIP RESCHEDULED OUT OF ZZZ FOR 3RD LEG; AND NIGHT FALL MAY HAVE CAUSED THE MAINT REPRESENTATIVES AT ZZZ TO NOT LOOK AT THE APU WRITE-UP AND AGAIN THE FO MAY HAVE MISSED SEEING THE DEPLOYED APU RAM AIR INTAKE NOR NOTICE THE PWR INCREASE AS WE WERE VECTORED CLOSE ABEAM FOR A RWY 13 VISUAL APCH. THE OPEN APU RAM AIR DOOR WAS NOTED ON ARR AT LGA. I HAD LITTLE TIME IN BTWN FLTS TO MAKE A WALKAROUND AND TRUSTED THE MECHS TO DISPATCH US IN THE CORRECT DOOR CONFIGN FROM ZZZ ON EITHER LEG CONSIDERING THAT WE HAD TO HAVE AN AIR CART TO START ENGS AND PCA TO KEEP THE PLANE COOL; ALL OF WHICH HAD TO BE PLUGGED IN UNDER THE TAIL OF THE ACFT IN THE VICINITY OF THE APU INLET DOORS. DID ALL OF THESE FOLKS MISS THE DEPLOYED RAM INLET DOOR?