TECH TIP FOR SEPTEMBER, 1995

A CUSTOMER REPORTS ON HAVING A 1989 ASTRO W/4.3L WITH A NO CHARGE SITUATION. THE INDICTOR LIGHT ON THE DASH WORKED PROPERLY WHEN THE KEY WAS TURNED ON, BUT WOULDN'T GO OUT COMPLETELY WHEN THE ENGINE WAS RUNNING. (SIMILAR TO WHAT THE OLDER DELCO "SI" ALTERNATORS WILL DO IF THE DIODE TRIO IS BAD, EXCEPT THIS ALTERNATOR DOESN'T HAVE A TRIO.) IF THE ENGINE WAS REVVED WAY UP THERE, THE LIGHT WOULD DIM FURTHER BUT WOULD NOT GO OUT, AND THE ALTERNATOR WAS NOT CHARGING AT FULL OUTPUT VOLTAGE. THE ALTERNATOR WAS BROUGHT TO ME FOR REPAIR AND AFTER TESTING, I SENT IT BACK "NOTHING WRONG". TESTING OF WIRING CIRCUITS SHOWED NOTHING, AS THERE APPEARED TO BE FULL VOLTAGE ON ALL NECESSARY CONNECTIONS. IT WAS FINALLY DETERMINED, BY A PROCESS OF ELIMINATING ONE WIRE AT A TIME THAT THE MAIN BATTERY CONNECTION TO THE BACK OF THE ALTERNATOR, WHILE IT HAD 12 VOLTS ON IT WAS NO CAPABLE OF CARRYING CURRENT. THE CUSTOMER FOUND THAT THERE IS A BREAKER-PROTECTED CONNECTOR ON THE FIRE WALL, AND HE JUMPED MAIN BATTERY POWER TO THERE. THE ALTERNATOR NOW WAS CONNECTED TO THE REST OF THE ELECTRICAL SYSTEM AND THE PROBLEM WAS SOLVED.

SOMETIMES THE EASIEST WAY TO IDENTIFY A CHARGING PROBLEM THAT YOU BELIEVE IS RELATED TO WIRING, IS TO OBTAIN THE PROPER PLUGS AND ELIMINATE ONE AT A TIME UNTIL THE PROBLEM CIRCUIT IS LOCATED. FOR THOSE OF YOU WHO HAVEN'T RUN INTO THIS ENGINE, HERE IS A WARNING! ON THE GENERAL'S VEHICLES USING THE 3.4L 24 VALVE FOUR CAM ENGINE THE TIME REQUIRED TO CHANGE THE ALTERNATOR OR THE STARTER IS EXTRAORDINARY. THE ALTERNATOR REQUIRES 4-5 HOURS IF THE CAR IS A STANDARD AND A FULL 5 HOURS IF IT'S AN AUTOMATIC. THE STARTER WILL TAKE ABOUT 3-4 HOURS IF YOU LOOK AT IT CAREFULLY AND THINK ABOUT WHAT YOU ARE GOING TO DO NEXT. IT MUST BE REALLY FUN TO TELL THE CUSTOMER THAT THE ALTERNATOR OR STARTER COSTS $170.00 BUT THE LABOUR IS $250.00 TO $350.00 MORE. THE ANSWER IS REALLY:

" I DIDN'T DESIGN IT, BUILD IT, BUY IT, OR BREAK IT. ALL I HAVE TO DO IS FIX IT, AND YOU HAVE TO PAY THE BILL".

WHILE READING A TRADE PUBLICATION YESTERDAY I CAME ACROSS A "GEM" OF AN IDEA. FORD HAS TAKEN SOME OF THEIR SEPARATE CIRCUIT CONTROLLER AND PUT THEM ALL IN ONE MICRO-PROCESSOR CONTROLLED PACKAGE, THEY CALL A "GEM" (GENERIC ELECTRONIC MODULE). THE GEM UNIT FIRST APPEARED ON THE NEW WINDSTAR BUT HAS OR WILL SPREAD TO THE REST OF THE PRODUCT LINE. FROM THE ARTICLE, " THE GEM COMBINES THE FUNCTION OF MANY SEPARATE CONTROLLERS. IT CAN OPERATE HIGH CURRENT RELAYS OR FEED LOW CURRENT INTERIOR LIGHTS DIRECTLY. IT PROVIDES SELF-TEST, CONTINUOUS TEST AND WIGGLE TEST. IT ALSO MONITORS ITS OWN INPUT AND OUTPUT AND CAN PROVIDE SERIAL COMMUNICATION WITH THE Service Bay Diagnostic System (SBDS) THROUGH THE VEHICLE'S 16 PIN Data Link Connector(DLC).SOME OF THE ACCESSORIES OPERATED BY THE "GEM" ARE REAR WINDOW DEFROST, WINDSHIELD WIPERS, SLIDING MEMORY DOOR LOCKS, ONE-TOUCH POWER WINDOWS, WARNING LAMPS, INTERIOR LIGHTS, BATTERY SAVERS, AND SPEED DEPENDENT WIPERS."                      

THE BATTERY SAVER MODE IS A BLESSING IN THAT IT WILL POWER UP THE INTERIOR LIGHTING SYSTEM FOR ONLY 40 MINUTES AFTER THE KEY IS TURNED OFF. THIS WILL PREVENT DEAD BATTERIES EVEN IF THE DRIVER FORGETS TO TURN OFF THE LIGHT OR THE DOOR IS LEFT AJAR. SINCE THE "GEM" MONITORS THE INPUTS AND OUTPUTS OF ALL CIRCUITS UNDER ITS CONTROL AND CAN SET DIAGNOSTIC TROUBLE CODES INDICATING ANY OUT OF RANGE READINGS, THE PRACTICE OF CUTTING OR SPLICING INTO THE WIRING SYSTEM IS FORBIDDEN. THE EXTREME SENSITIVITY OF THIS SYSTEM WILL NOT ALLOW CUTTING AND SPLICING INTO THE HARNESS, NOR WILL IT PERMIT THE ADDITION OF A CIRCUIT TO THE FUSE PANEL.

EVEN THE SELECTION OF REPLACEMENT BULBS IS CRITICAL. THE SYSTEM IS DESIGNED TO INDICATE A MALFUNCTION IF ANY EXTRA CURRENT ( IN MILLIAMPS) IS PASSED THROUGH ITS CIRCUITS. ADDING ALARMS OR EXTRA STEREOS WILL PLAY HAVOC WITH THE SYSTEM. THE WRITER OF THE ARTICLE GOES ON TO SAY THAT HE HEARD OF A STEREO SHOP WHO ADDED A CD PLAYER TO A WINDSTAR AND THE DOOR LOCKS, WINDOWS AND WIPER STARTED OPERATING BY THEMSELVES.