Text Box: THIS IS HOW I REPAIRED THE SENDING UNIT ON MY 84 GRAND NATIONAL THIS IS HOW I DIAGNOSED AND REPAIRED THE FUEL LEVEL SENDING UNIT ON MY 84 GRAND NATIONAL. IT SHOULD NOT MATTER WHAT YEAR YOUR TURBO REGAL IS BECAUSE THEY ALL WORK THE SAME WAY. THE ONLY THING IS THE WIRE COLOR IS DIFFERENT ON SOME 86's & ALL 87's AND HOW IT COMES APART. THE TROUBLESHOOTING WOULD BE THE SAME JUST USE THE APPROPRIATE WIRE COLORS. WHAT YOU NEED FOR REPAIRS. OHM METER SCOTCH BRITE PAD PENCIL WITH A GOOD ERASER PLIERS SMALL SCREW DRIVER TO PRY OFF FUEL SOCK THIS IS EASY IF YOU CAN USE AN OHM METER AND HAVE SOME MECHANICAL ABILITY AND SHOULD TAKE LESS THAN 1/2 HOUR. YOU WILL HAVE TO REMOVE YOUR GAS TANK AND SENDING UNIT. THE TANK IS STILL FULL OF GASOLINE VAPORS. CAUTION AND COMMON SENSE MUST BE USED AT ALL TIMES. IF YOU HAVE ANY DOUBTS STOP !!! AND HAVE SOMEONE ELSE PERFORM THE REPAIRS FOR YOU. I ASSUME NO RESPONSIBILITY FOR ANY INJURY OR DAMAGE THAT MAY OCCUR FOR THE FOLLOWING BEFORE YOU REMOVE YOUR GAS TANK  CHECK THE SENDING UNIT FIRST WITH AN OHM METER TO CONFIRM THAT IT IS NOT WORKING. UNPLUG THE FUEL PUMP WIRE CONNECTOR AND  MEASURE THE RESISTANCE BETWEEN THE SIGNAL AND GROUND WIRES. DO NOT GO TO A CHASSIS GROUND OR TEST WILL NOT WORK BECAUSE THE SENDING UNIT IS NOT GROUNDED WHEN THE PLUG IS DISCONNECTED. DEPENDING ON THE LEVEL  IN THE TANK YOU SHOULD HAVE BETWEEN  0 OHMS( empty)  AND  90 OHMS (full). IF YOU GET AN OPEN OR A VERY HIGH RESISTANCE THE SENDING UNIT IS NOT WORKING PROPERLY. 84/85 86/87 UNITS WITH AN ORANGE CONNECTOR 84/85 THE WIRE COLORS ARE TAN (12 V + TO FUEL PUMP), PINK ( SIGNAL FROM SENDING UNIT) AND BLACK ( GROUND) . UNITS WITH A BLACK CONNECTOR 86/87 THE WIRE COLORS ARE GRAY( +12V TO FUEL PUMP), PURPLE( SIGNAL FROM SENDING UNIT) AND BLACK (GROUND). THE SENDING UNIT VARIES THE  RESISTANCE  BETWEEN 0 & 90 OHMS ON THE SIGNAL WIRE AS THE LEVEL IN THE TANK CHANGES.  ON 86/87 UNITS  THE OPERATION WOULD BE THE SAME SO THE SAME TROUBLESHOOTING PRINCIPLES WOULD APPLY. I DON'T KNOW HOW IT COMES APART EITHER, IT SHOULD BE SIMILAR AND ITS NOT BRAIN SURGERY. THE COUPLE OF SENDING UNITS I HAVE FIXED HAD THE SAME PROBLEM. THE CONTACTS BETWEEN THE PIVOTING FLOAT ARM AND THE STATIONARY BASE BECOME DIRTY AND NO LONGER MAKE CONTACT. THIS WILL CAUSE A VERY HIGH RESISTANCE READING WHEN YOU PERFORM THE ABOVE TEST AND WILL USUALLY CAUSE THE GAS GAUGE TO ALWAYS READ FULL. NINE EASY STEPS TO A WORKING SENDING UNIT BACK TO MAIN PAGE Created 2/19/06 Last Edited 2/10/07