TECH TIP FOR SEPTEMBER, 1993

ON EARLY 1980'S GM "F" BODY CARS (CAMERO, FIREBIRD, TRANSAM),WITH ELECTRICALLY CONTROLLED CARBURETORS THERE CAN BE A SPECIAL PROBLEM, AND IT GOES LIKE THIS:

THE CUSTOMER COMPLAINS OF A DEAD BATTERY AND ALL INDICATIONS ARE THAT THE ALTERNATOR IS AT FAULT, BUT WHEN THE ALTERNATOR IS REPLACED IT STILL WON'T CHARGE AND THE IDIOT LIGHT AND CHOKELIGHT STAY ON. (IF THERE IS ONLY A VOLT GAUGE IT WILL READBATTERY VOLTAGE ONLY).

FURTHER INVESTIGATION MIGHT SHOW A BLOWN GAUGE FUSE, BUTREPLACING IT WILL NOT FIX THE PROBLEM AS IT WILL ONLY BLOWAGAIN.(HOPEFULLY RIGHT AWAY AND NOT 5 MINUTES AFTER YOUR CUSTOMER LEAVES YOUR SHOP)

THE PROBLEM IS APPARENTLY THAT THE CHOKE RELAY IS DRIVEN OFF THE ALTERNATOR DIODE TRIO TERMINAL AND THE WIRING GOES TO THE CHOKE RELAY PANEL WHICH IS LOCATED ALMOST ABOVE THE DRIVER'S RIGHT FOOT. HERE A LOOM OF ABOUT 4 OR 5 WIRES WRAPS AROUND THE STEERING COLUMN BRACKET AND PLUGS INTO THE INSTRUMENT PANEL.

THESE WIRES RUB AGAINST THE SHARP EDGES OF THE STEERING COLUMNBRACKET AND EVENTUALLY SHORT TO GROUND CAUSING THE FUSE TO BLOW AND THE ALTERNATOR TO SHUT DOWN. THE DIAGNOSIS AND REPAIR CAN BE VERY TIME CONSUMING, AND AS THESE CARS AGE THE INCIDENCE WILL UNDOUBTEDLY INCREASE. (JUST SOMETHING ELSE TO LOOK FORWARD TO)

90&92 LUMINA'S HAVE A PROBLEM WHICH CAUSES THE BATTERY TO DRAIN. THE PROBLEM WAS ADDRESS BY GM SERVICE BULLETIN 91-296-10, DATED APRIL 1991 BUT HAS SINCE BEEN UPDATED TO INCLUDE THE 1992 MODEL.

THE PROBLEM IS CAUSED BY THE SEAT BELT RESTRAINT SOLENOIDREMAINING "ON". THIS IS CAUSED BY THE OUTSIDE DOOR HANDLE LEVERAND LOCKING ROD INTERFERING WITH THE MECHANISM. THIS MAY BE AN INTERMITTENT PROBLEM BECAUSE SLAMMING THE DOOR OR OPERATING THE OUTSIDE HANDLE MAY JIGGLE THE MECHANISM BACK INTO PLACE.

TO DIAGNOSE THE PROBLEM, SIT IN THE VEHICLE, LOCK THE DOORS, ANDACTIVATE THE INSIDE HANDLES INDIVIDUALLY. LISTEN FOR THESOLENOIDS IN THE DOOR TO "CLICK" WITHIN 3©5 SECONDS AFTER THEHANDLE WAS RELEASED. IF YOU DON'T HEAR THE SOLENOIDS DISENGAGING, THEN IT MAY BE HUNG UP ON THE LINKAGE.

TO CORRECT THE PROBLEM, REMOVE THE DOOR LINER AND WATER DEFLECTOR AND DISENGAGE THE OUTSIDE HANDLE FROM THE LOCK ROD. REMOVE THIS AS WELL AS THE OUTSIDE HANDLE. THE CONDITION IS CAUSED BY THE LOCKING ROD RESTING ON THE FLAT OF THE LINKAGE INSTEAD OF IN ITS GROOVE. FILE THE RADIUS OF THE LINKAGE GROOVE AND DE©BURR IT SO THAT THE ROD CAN NO LONGER ACCIDENTALLY REST ON THE FLAT. REªASSEMBLE AND CHECK FOR PROPER OPERATION.

SOURCE: CHEV. SERVICE BULLETIN SEPT,1992/ ELECTRICAL CONNECTIONJULY, 1993.

WITH THE MANUFACTURERS OF STARTER AND ALTERNATORS INCREASING THEIR USE OF DIS SIMILAR METALS IN THE CONSTRUCTION OF THEIR PRODUCTS, THE PROBLEM OF CORROSION OR GALVANIC ACTION HAS INCREASED TO THE POINT THAT WE MUST TAKE THE POSITION THAT WE CAN NO LONGER BE RESPONSIBLE FOR DAMAGE TO HOUSINGS CAUSED BY PARTS SEIZURE OR FASTENER BREAKAGE DURING DISASSEMBLY FOR THE PURPOSES OF EFFECTING REPAIRS. IT WILL BE NECESSARY TO CHARGE FOR ANY PARTS OR ADDITIONAL LABOUR CAUSED BY THIS PROBLEM. 

SPECIAL NOTICE

LAST MONTH I TOUCHED ON THE REPLACEMENT OF THE STOCK ALTERNATOR WITH ONE OF A HIGHER OUTPUT, BUT PERHAPS I DID NOT MAKE CLEAR THE NORMAL REASON FOR DOING THIS AND ITS ASSOCIATED PROBLEMS.

MOST OF THESE REPLACEMENTS ARE TO ACCOMMODATE "KILLER" STEREO SYSTEMS WHICH REQUIRE MORE POWER THAN THE ORIGINAL UNIT COULD PRODUCE AND LEAD TO PREMATURE ALTERNATOR AND BATTERY FAILURE.

AN ALTERNATOR IS CAPABLE OF PRODUCING ITS FULL RATED OUTPUT FOR ONLY A SHORT PERIOD OF TIME, USUALLY NO MORE THAN ABOUT 20MINUTES WITHOUT DOING DAMAGE TO THE UNIT CAUSED BY OVERHEATING.

THE CONTINUOUS OUTPUT CAPABILITY OF AN ALTERNATOR IS ABOUT 80% OF WHAT IT RATED FOR. WITH THE LIGHTING SYSTEM TAKING ABOUT 20 AMPS, HEATER FAN 8-12, WIPERS 10-15 (NOT COUNTING POWER WINDOWS OR SEATS OR OTHER OPTIONS), AND THE REQUIREMENT TO RECHARGE THE BATTERY AFTER THE START SEQUENCE, THE STRAIN ON AN ALTERNATOR IS ALREADY HUGE WITHOUT THE HIGH OUTPUT STEREO.

IF THE ORIGINAL ALTERNATOR FAILED BECAUSE OF OVER WORK, THEN THE REPLACEMENT WILL ALSO FAIL FOR THE SAME REASON, IF IT IS NOTUPGRADED, AND MAYBE EVEN IF IT IS. THE CAPACITY OF ALTERNATORS IS LIMITED (SEE TECH TIP SEPT. 1992) AND IT MAY NOT BE POSSIBLE TOSUPPLY ENOUGH POWER WITH ONE ALTERNATOR OR EVEN POSSIBLY WITH 2.

TO BE UNAWARE THAT THERE IS ONE OF THESE "KILLER" STEREOS IN A CAR AND JUST REPLACE THE ALTERNATOR WITH WHAT WAS THERE IS BEGGING FOR THE CUSTOMER TO BE REALLY UNHAPPY WHEN HE HAS TO COME BACK HAVING BEEN STRANDED SOME PLACE. IN ADDITION THE POSSIBILITY EXISTS THAT WHEN I FIND OUT I WILL DENY WARRANTY DUE TO MIS APPLICATION AND THEREFORE ABUSE.

THERE IS MONEY TO BE MADE UPGRADING THE SYSTEM TO HANDLE THESE STEREOS BUT FIRST YOU HAVE TO BE WILLING TO TELL THE CUSTOMER THAT WITHOUT UPGRADING AND MAYBE EVEN WITH UPGRADING, THERE WILL BE NO WARRANTY ON ELECTRICAL SYSTEM WORK WHERE THERE IS AN OVERLY LARGE STEREO INVOLVED, BETTER TO LET SOMEONE ELSE HAVE THE HEAD ACHES.  

A SEA CAPTAIN WAS SAILING THROUGH A REALLY THICK FOG WHEN HESPOTED A LIGHT ON A COLLISION COURSE. HE GIVES THE ORDER TO HISCOMMUNICATIONS OFFICER TO CONTACT THE OTHER SHIP AND TELL HIM TO CHANGE COURSE. THE ANSWER COMES BACK THAT IT'S THE SEA CAPTAIN WHO WILL HAVE TO CHANGE.

THE SEA CAPTAIN IS FURIOUS!! HOW DARE THEY REFUSE!! THE SEACAPTAIN BARKS " TELL HIM I AM A CAPTAIN IN THE U.S. NAVY © CHANGEYOUR COURSE!" THE ANSWER CAME BACK " I AM A SEASONED NAVIGATOR  YOU CHANGE YOUR COURSE". THE SEA CAPTAIN THREATENED " WE ARE A DESTROYER, LOADED WITH NUCLEAR WEAPONS, NOW CHANGE YOUR COURSE".

THE ANSWER WAS " WE ARE A LIGHT HOUSE"

A FRIEND TOLD ME OF THIS STORY, AND I AM REMINDED THAT WE ALL SOMETIMES MISS OBVIOUS THINGS BECAUSE OUR KNOWLEDGE OR CREDENTIALS MAKE US BLIND. BUT, DON'T WORRY ABOUT IT, AFTER ALL HE WHO NEVER MADE A MISTAKE  NEVER DID ANYTHING. MY FRIEND WAS TELLING ME ABOUT A FOOLISH THING HE HAD DONE AND BLAMED IT ON OVERWORK SAYING THAT HE WAS TAKING A FEW DAYS OFF TO REGROUP.

IF YOU ARE TAKING SOME TIME OFF, DO YOURSELF A FAVOUR, FORGETABOUT WORK AND IT'S PROBLEMS. THEY WILL STILL BE THERE WHEN YOU GET BACK BUT IF YOUR WELL RESTED YOU WILL BE BETTER ABLE TO HANDLE THEM, AND THEY PROBABLY WON'T BE AS BAD AS WHAT THEY WERE BEFORE YOU WENT LEFT.