why wont my 1999 gmc safari hold a charge as far as battery alternator goes. on 1999 GMC Safari

i replaced the battery 3 times, replaced the alternator 3 times install a new battery cable (positive)replaced the starter, replaced the the alternator plug and check all the fuse in the fuse boxes under the dash and under the hood and still no charge.

by in Chicago, IL on October 30, 2012
3 answers 10 comments
ANSWER by on October 30, 2012
Are you saying that the battery wont hold a charge or the charging system isnt working? It the battery is losing the charge, (it goes dead) after a day or so then you should be looking for a current draw. Something is staying on and killing the battery. If the charging system isnt working then you need to do some diagnostics to see why the alternator is not doing its job.
COMMENT by on October 30, 2012
the charging system is not working properly even after all the repairs i recently made to it
COMMENT by on October 30, 2012
WHAT IS THE VOLTAGE AT THE BATT.WITH THE ENGING RUNNING?
COMMENT by on October 30, 2012
The voltage is between 9 and 10
COMMENT by on October 30, 2012
CHECK THE BIG RED WIRE ON THE BACK OF THE ALT. SHOULD BE BATTERY VOLTAGE IS IT? WHEN YOU INSTALLED THE ALT WAS THE BATT. CHARGED UP BEFOR YOU STARTED THE ENG. AND NOT JUST JUMP STARTED? 9-10 VOLTS YOU NEED TO HOOK UP A CHARGER AND GET BATTERY TO FULL CHARGE THEN TRY CHECKING VOLTAGE. THIS IS SUPPOSED TO BE AN EASY ONE. BUT SOMETIMES WELL.
COMMENT by on October 30, 2012
The battery was brand new then I put the 3rd alternator on and still no charge
ANSWER by on October 30, 2012
wow, three batteries and three alternators...why didn't you get ANOTHER alternator? anyway, Jae Mak...sounds like you have an issue with the alternator not charging...you have to find out what wire is missing or broken.
COMMENT by on October 30, 2012
Problem I dnt have or know how to use one thar test lights
COMMENT by on October 30, 2012
I UNDERSTAND YOU WANTING TO FIX THIS YOURSELF BUT IT IS TIME TO GO SEE A MECHANIC!! THE REPAIR SHOULD NOT COST YOU A BUNCH. DON'T BE DISCOURAGED THOUGH YOU WERE ON THE RIGH TRACK.
ANSWER by on November 01, 2012
Pull the alternator off and have it 'bench tested'. IF it checks out good , leave it off truck. Next , fully slow-charge battery and then buy a multi-meter. Then get a wiring diagram of charging circuit and perform input/output and continuity tests on appropriate wires. Probably failed signal wire to alt. VERIFY FIRST!!! Before putting on more parts.........IF alt. bench tests bad then have the next one you get bench tested before you leave the store with it. Then troubleshoot vehicle before installing alt. Good luck.
COMMENT by on November 01, 2012
Bench tested by whom? AutoZone? Heck NO! They think anything with "duralast" on it is good to avoid warranty issues and fail anything else that comes in...to sell a "duralast".
COMMENT by on November 01, 2012
I ll try it once the weekend comes along
COMMENT by on November 02, 2012
Good luck. I suggest you ask friends for references to a trustworthy shop.