TECH TIP FOR SEPTEMBER, 1997

THIS WILL BE FAIRLY SHORT TECH TIP AND IT CONCERNS THE REGULATOR PLUGS OF DELCO ALTERNATORS. UP UNTIL ABOUT THE 1986 MODEL YEAR MOST GM CARS WERE EQUIPPED WITH THE "SI" SERIES OF ALTERNATORS. THE "SI" SERIES WAS IDENTIFIABLE BY THE 2 WIRE PLUG TO THE REGULATOR WHICH USUALLY CONTAINED A LARGE RED WIRE AND A SMALLER WHITE/BROWN WIRE. THE RED WIRE IS CONNECTED TO THE SENSE CIRCUIT AND AS THE NAME IMPLIES IT IS HOW THE REGULATOR TELLS THE STATE OF CHARGE OF THE BATTERY. IF THIS WIRE IS DISCONNECTED THE ALTERNATOR WILL STOP CHARGING, MORE IMPORTANTLY, IF THERE IS A HIGH RESISTANCE CONNECTION AT THIS TERMINAL THE REGULATOR WILL CAUSE THE ALTERNATOR TO OVER CHARGE AND CAN EASILY DAMAGE THE BATTERY. THE WHITE/BROWN WIRE IS THE "IGNITION" FEED AND TELLS THE REGULATOR TO TURN ON AND ALLOW THE ALTERNATOR TO CHARGE. THE FEED TO THIS TERMINAL USUALLY GOES THROUGH THE INDICATOR LIGHT, AND A FEED AS LOW AS 9 VOLTS WILL USUALLY CAUSE THE ALTERNATOR TO CHARGE BUT IT HAVE NOTHING TO DO WITH HOW HARD THE ALTERNATOR WILL CHARGE.

BEGINNING IN THE 1986 MODEL YEAR GM STARTED USING THE "CS" SERIES OF ALTERNATORS. THIS IS QUITE A REMARKABLE UNIT IN THAT IT PRODUCES A LARGE OUTPUT FROM A RELATIVELY SMALL ALTERNATOR. IT IS UNFORTUNATE THAT IT HAS GAINED SUCH A BAD REPUTATION IN THE GARAGE INDUSTRY. ALL OF THE PROBLEMS THAT THE ALTERNATOR HAS CAN BE TRACED BACK TO POOR CAR DESIGN AND OVER WORK.

CONSIDER THAT AN ALTERNATOR IS ONLY ABOUT 50% EFFICIENT AND FOR EVERY WATT OF POWER IT PRODUCES FOR THE BATTERY/CAR, IT ALSO, PRODUCES A WATT OF HEAT. NOW CONSIDER THAT A 105 AMP "CS" SERIES ALTERNATOR, WHEN WORKING FULL OUT IS PRODUCING ABOUT 1500 WATTS OF POWER FOR THE CAR AND ABOUT THE SAME AMOUNT OF HEAT. THIS IS THE OUTPUT OF AN 8 FOOT BASE BOARD HEATER. NOW STUFF THE BACK OF THE ALTERNATOR UP AGAINST AN ENGINE WHICH IS MAKING HUNDREDS OF DEGREES OF HEAT, AND ASK YOURSELF WHY THESE ALTERNATORS OVER HEAT, MELT THE SOLDER IN THE RECTIFIERS, AND BOIL THE GREASE OUT OF THE END BEARINGS.

IN MY SHOP WE HAVE SEEN 2 OF THE "CS" SERIES WHICH FAILED BECAUSE THEY HAD WORN THEIR BRUSHES OUT. BOTH OF THESE UNITS WERE INSTALLED ON FULL SIZE PICK UP TRUCKS WITH SMALL V6 ENGINES AND BOTH LASTED FOR OVER 275,000 KM. THE SECRET HERE WAS THAT NEITHER WAS BADLY OVER WORKED AND THEY COULD GET ALL THE COOLING AIR THEY NEEDED. THE FAULT HERE LIES IN OURSELVES THAT WE WANT ALL THIS ELECTRICAL POWER AND SUCH BIG ENGINES ALONG WITH A SWOOPY DESIGN WHICH DOESN'T LEAVE ENOUGH ROOM FOR THE MECHANICALS. HAVING SAID THAT AND SEEN THE RESULTS WITH THE "CS" ALTERNATOR, WHAT DO YOU THINK OF CHRYSLER ADS THE SAY "LESS ROOM FOR THE MECHANICALS MEANS MORE ROOM FOR THE PEOPLE"? THEY BETTER HAVE MORE ROOM FOR THEIR WALLETS TOO!

THE WIRING FOR THE"CS" ALTERNATOR IS ALSO DIFFERENT FROM WHAT WE ARE USED TO. AT THE LAST COUNT THERE WERE 14 REGULATOR INSTALLED IN THE "CS" SERIES, AND WHILE EACH HAS IT'S OWN SPECIAL FUNCTIONS LIKE SOFT WALK IN, TIME DELAY, TEMPERATURE SENSE, & LOAD RESPONSE THE WIRING IS SO FAR VERY SIMILAR BETWEEN ALL OF THEM. PLEASE NOT I SAID SIMILAR NOT SIMPLE. I CONTACTED THREE REGULATOR MANUFACTURERS AND ASKED FOR AN EXPLANATION OF THE FUNCTIONS OF THE FOUR PINS FOUND IN THE " CS" REGULATORS, AND AFTER WADING THROUGH THE RESULTS, I BELIEVE THAT THE EXPLANATION GIVEN BY TERRY MADY, A REBUILDER AT OAKVILLE STARTER ALTERNATOR, IS THE MOST DOWN TO EARTH AND READABLE. THAT EXPLANATION FOLLOWS AND I SUGGEST THAT YOU READ IT VERY CAREFULLY, BECAUSE IF YOU DON'T YOU WILL BE MORE CONFUSED THAN IF YOU HADN'T READ IT AT ALL.