TECH TIP FOR JULY, 1998

RECENTLY A MAN BROUGHT ME HIS CAR SAYING THAT HIS ALTERNATOR HAD FAILED WHEN HE WAS OUT OF TOWN ON THE WEEKEND AND HE HAD IT REPLACED. NOW THE CAR WAS DOING THE SAME THING, IT SEEMED TO BE ALRIGHT UNLESS YOU TURNED ANYTHING ON AND THEN THE VOLT GAUGE WOULD DROP UNTIL IT FINALLY GOT INTO THE RED, AND WOULD I CHECK IT OUT? I DON'T DO SERVICE BUT I TOOK A METER OUT AND CHECKED THE OUTPUT AT BOTH THE BATTERY AND THE ALTERNATOR. THE CAR IN THIS CASE IS A LATE MODEL GM PRODUCT WHICH HAD A NEW DUAL POST BATTERY AND A NEW ALTERNATOR. I FOUND A SMALL BUT SIGNIFICANT DIFFERENCE IN THE VOLTAGE READINGS BETWEEN THE ALTERNATOR AND THE BATTERY AND SUGGESTED THAT HE SHOULD TAKE IT TO A GARAGE TO HAVE THE SYSTEM PROPERLY CHECKED.

THE GARAGE OWNER CALLED LATER AND SAID THAT IT TURNED OUT TO BE THE NEW BATTERY THAT WAS BAD, BUT HE HAD A REAL JOB FINDING IT. HE HAD TESTED EVERYTHING AND FINALLY CONDEMNED THE BATTERY. THE CUSTOMER TOOK THE BATTERY BACK TO THE SUPPLIER, WHO CHECKED IT AND DENIED WARRANTY, SAYING THAT THE BATTERY PASSED ALL THE TESTS.

THE GARAGE CALLED THE BATTERY SUPPLIER AND EXPLAINED WHAT HE HAD FOUND AND THE BATTERY WAS REPLACED IMMEDIATELY. THE EXPLANATION IS THAT THERE WAS A HUGE VOLTAGE DROP BETWEEN THE TOP AND SIDE POSTS OF THE BATTERY. THE CAR WAS HOOKED UP TO THE SIDE POSTS BUT WHEN EVERYONE FIRST CHECKED THE BATTERY THEY USED THE MORE CONVENIENT TOP POSTS.

THIS COMES FROM THE iatn VIA THE CANREBUILD NEW AND IS THE ANSWERTO A COMMON COMPLAINT BY CAR OWNERS.

1997 PONTIAC BONNEVILLE W/3.8L ENGINE AND A FULL GAUGE PACKAGE.

COMPLAINT: THE VOLTAGE GAUGE WILL DROP INTO THE RED AT IDLE WITHTHE LIGHTS AND A/C ON, WHEN IN DRIVE.

FIX: THIS IS NORMAL!.AN ALTERNATOR IS LIMITED IN OUTPUT BY HOW FAST IT IS TURNING. IF OFF IDLE OR UNLOADED THE SYSTEM CHARGES AT THE CORRECT VOLTAGE, THEN THE SYSTEM IS PROBABLY FINE.

!! NOTE !! - GENERAL MOTORS ISSUED A BULLETIN COVERING THIS ABOUT 2 YEARS AGO. REPLACING THE ALTERNATOR WITH A HIGHER OUTPUT UNIT WILL PROBABLY NOT SOLVE THE PROBLEM, A SMALLER PULLEY MIGHT MAKE THE SITUATION LESS NOTICEABLE. THE CAR DESCRIBED AT THE BEGINNING HAD ITS COMPLETE DASH AND MOST OF ITS WIRING REMOVED FOR CHECKING BEFORE THEY FOUND THE ANSWER.

1992 NISSAN MAXIMA W/3.0L ENGINE COMPLAINT CHARGING SYSTEM OPERATING AT 16.4 - 17.9 VTS. AND THE INDICATOR LIGHT FLICKING. CAR HAD A NEW NISSAN REMANUFACTURED ALTERNATOR INSTALLED.

FIX: FOUND THE WIRING TO THE ALTERNATOR RUBBED THROUGH ON THE RIGHT SIDE OF THE ALTERNATOR SUPPORT. ALSO FOUND A LARGE AMOUNT OF CERESIN ON AND AROUND THE ALTERNATOR TERMINALS.

1994 MERCURY VILLAGE W/3.0L ENGINE

COMPLAINT: WHEN THE VAN WILL START, IT DOES AND RUNS FINE,BUT IT HAS AN INTERMITTENT PROBLEM WHICH WILL CAUSE A NO CRANK CONDITION.

FIX: THERE WAS A BROKEN WIRE INSIDE THE INSULATION AT THE 2 TERMINAL CONNECTOR THAT COMES FROM THE SAFETY NEUTRAL SWITCH. THIS 2 WIRE CONNECTOR ALLOWS POWER TO PASS THROUGH THE NEUTRAL SWITCH AND ON TO THE INHIBIT SWITCH.

1993 BMW 318i W/2.3L ENGINE

COMPLAINT: THE CAR WILL NOT SHUT OFF UNLESS YOU DISCONNECT THE BATTERY OR REMOVE THE #31 FUSE.

FIX: THE PROBLEM WAS IN THE INSTRUMENT CLUSTER CIRCUIT BOARD. THE #31 FUSE IS THE POWER SUPPLY AND IS HOT ALL THE TIME. THE SHORTED BOARD WAS USING THIS TO POWER UP THE #23 FUSE WHICH KEPT THE IGNITION HOT ALL THE TIME.