RADIO COM PROB NOTWITHSTANDING. ATX PLT CONTINUES TO DEST ARPT. CITES ACFT ELECTRICAL ELECTRONIC PANEL DESIGN PROB.

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THE SECOND INCIDENT EXPERIENCED DURING THIS FLT WAS COM DIFFICULTY WHICH RESULTED FROM EQUIP FAILURE ON MY ACFT. I HAD DIFFICULTY STARTING THE ACFT DUE TO A WEAK BATTERY. ON RUN UP CHK THE AMP METER INDICATED NORMAL OP OF THE ALTERNATOR SO I HAD NO REASON TO SUSPECT FURTHER DIFFICULTY. ALTHOUGH I DID NOT DETECT IT AT THE TIME; THE WEAK BATTERY AND POSSIBLE LOW CHARGE RATE MAY HAVE BEEN EFFECTING MY COMS EQUIP AT THE TIME I WAS PREPARING TO DEPART. IMMEDIATELY AFTER DEP I ATTEMPTED TO CONTACT TWR TO REQUEST A TURN ON COURSE. TWR DID NOT RESPOND AND ON MY SECOND ATTEMPT I NOTICED THAT MY XMISSION DID NOT SOUND NORMAL. I SWITCHED RADIOS AND TRIED AGAIN BUT NOTICED THE SAME INDICATION THAT I WAS NOT GETTING OUT. I THEN HEARD TWR TALKING TO ANOTHER ACFT BUT THE RECEPTION WAS WEAK AND BARELY READABLE. REALIZING I HAD A PROBABLE LOW VOLTAGE CONDITION I TURNED OFF ALL ELECTRICAL EQUIP EXCEPT THE XPONDER AND MY #1 COM RADIO. I WAS IMMEDIATELY ABLE TO CONTACT TWR AND WAS INSTRUCTED TO MAKE L TFC AND CONTACT DEP WHEN ESTABLISHED ON XWIND. I DO NOT BELIEVE I MISSED ANY COMS WITH TWR. AFTER COMPLETING THE L TURN I CONTINUED TO TROUBLE-SHOOT THE PROB AND CALLED DEP. MY INITIAL CONTACT WITH DEP WAS DIFFICULT AND REQUIRED SEVERAL EXCHANGES TO ESTABLISH RADAR CONTACT AND OBTAIN ON COURSE INSTRUCTIONS. EVENTUALLY I WAS ABLE TO GET THE ALTERNATOR ON LINE AND CONFIRM IT'S OP BY A POS DEFLECTION OF THE AMP METER INDICATOR. BELIEVING MY PROB WAS RESOLVED I DECIDED TO CONTINUE TO MY DEST. COMS WITH DEP REMAINED STRONG AND NORMAL UNTIL I WAS GIVEN FREQ CHANGE ABOUT 25 MI OUT FROM MFE. I CONTACTED SAN ANGELO FSS AND OPENED MY VFR FLT PLAN. APPROX 2/3 OF THE WAY TO LAREDO (LRD); MY DEST; I TURNED ON A VOR RECEIVER. NO SIGNAL RECEPTION WAS INDICATED. I ATTEMPTED TO CONTACT FSS WITHOUT SUCCESS. REALIZING I MAY ARRIVE AT LRD WITHOUT COM CAPABILITY I REVIEWED THE VFR SECTIONAL FOR ALTERNATIVES BUT FOUND NONE WHERE GND COMS WOULD BE AVAILABLE. I TURNED OFF ALL ELECTRICAL EQUIP IN HOPE THAT ENOUGH PWR MIGHT BE CONSERVED TO MAKE INITIAL CONTACT AT LRD. UPON ARRIVING AT LRD I TURNED THE COM RADIO ON AND ATTEMPTED TO CONTACT THE TWR. WHEN I WAS UNABLE TO MAKE CONTACT I CONTINUED INBOUND OBSERVING FOR TFC. I DETECTED AN ACFT DEPARTING RWY 17 SO I DSNDED TO TFC PATTERN ALT; APCHED AT A 45 DEG ANGLE TO RWY 17; MADE L HAND TFC; OBSERVING THE TWR FOR LIGHT SIGNALS AND LANDED ON RWY 17. THIS PROB WAS CAUSED BY EQUIP FAILURE AND INADEQUATE SYS CONDITION INDICATORS. THE ACFT WAS A PA-28-181. THE AMP METER ON THIS PARTICULAR ACFT NORMALLY HAS A VERY LOW AMP METER INDICATION; USUALLY LESS THAN 1 NEEDLE WIDTH ABOVE ZERO UNLESS FULLY LOADED WITH ALL ELECTRICAL SYS INCLUDING PITOT HEAT. THE ALT CAUTION LIGHT IS MOUNTED ON THE INST PANEL JUST BELOW A GLARE SHIELD AND IS A BUTTON TYPE WITH BACK LIGHTED LETTERS. IN DAYLIGHT IT IS VIRTUALLY IMPOSSIBLE TO DETECT WHETHER OR NOT THIS LIGHT IS ILLUMINATED. THIS PROB CAN BE RESOLVED BY INSTALLATION OF A DIFFERENT AMP METER WHICH WILL GIVE A MORE PROMINENT INDICATION OF CHARGING CONDITION AND INSTALLATION OF AN ALT FAILURE CAUTION LIGHT BETTER THAN THE WEAK BACK LIGHTED BUTTON TYPE WHICH IS CURRENTLY INSTALLED.