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Battery keeps dieing! Help! - 95 GT -

  • Thread starter Thread starter Igofaster13
  • Start date Start date Jan 23, 2007

Igofaster13

Member
Mar 9, 2006
170
3
19
San Diego
Jan 23, 2007
#1
  • Jan 23, 2007
  • #1
Ok, A month ago I replaced the battery, Fast foward to now & the battery keeps dieing. I went & exchanged the battery out, & it still is dieing out after a few hours of use. I tested the computer with the OBD 1 tester & it passed with no problems. I also put new neg. & pos. terminals on & checked about everything else I can electrical. I am kinda lost, but I can go on alldatapro.com so that helps. Anybody know what I can test or check out next?



Thanks
 

Igofaster13

Member
Mar 9, 2006
170
3
19
San Diego
Jan 23, 2007
#2
  • Jan 23, 2007
  • #2
I am going to try some of this our right now......................


Ensure drive belt tension is correct.
Check battery for loose or corroded connections and loose battery posts.
Remove battery hold down clamps and shields, then inspect for broken or cracked case or cover.
Ensure battery drain is less than 50 milliamps and battery is at capacity.
Measure voltage at "B+" terminal on back of alternator. If battery voltage is present, proceed to step 6. If less than battery voltage, repair open in "B+" circuit.
Measure voltage at voltage regulator test point "A." If battery voltage is present, proceed to step 7. If less than battery voltage, repair fuse or open in circuit between alternator "A" and power distribution box.
Measure voltage at voltage regulator test point "F." If battery voltage is present, proceed to step 8. If less than battery voltage, proceed to step 14.
Turn ignition switch to RUN and measure voltage at wiring harness terminal "I." If voltage is greater than one volt, proceed to step 9. If voltage is less than one volt, repair open or high resistance in circuit between alternator "I" and battery warning indicator.
Measure voltage drop between voltage regulator test point "A" and positive battery post. If drop is less than 0.25 volt, proceed to step 10. If drop is more than 0.25 volt, service circuit between alternator terminal "A" and power distribution box. Ensure fuse and connectors are in good condition.
Measure voltage at voltage regulator test point "F." If less than two volts, proceed to step 11. If more than two volts, proceed to step 14.
Remove one pin "S" connector from alternator. Measure voltage between "S" terminal and ground, then between "S" terminal and positive battery terminal. If voltage is less than one volt at both terminals, proceed to step 12. If voltage is more than one volt at either terminal, replace alternator.
Install "S" connector, start engine, turn headlamps ON and set blower speed to HIGH. With engine running at 2000 rpm, measure voltage drop between "B+" terminal of alternator and positive battery post. If voltage drop is less than 0.5 volt, proceed to step 13. If voltage drop is more than 0.5 volt, service "B+" circuit. Ensure fuse and connections are in good condition.
Use a jumper wire to connect voltage regulator test point "F" to negative battery post, then measure alternator output amperage at 2000 RPM. If output amperage is more than alternator rating, replace regulator. If rating is less than specified, refer to Output Test. See: In-Vehicle Testing\Output Test
Remove alternator, then the voltage regulator.
Measure resistance between alternator slip rings.
If resistance is 1-10 ohms, inspect for worn brushes or open brush leads. Replace as required.
If brushes are in good condition, replace voltage regulator.
 

Igofaster13

Member
Mar 9, 2006
170
3
19
San Diego
Jan 23, 2007
#3
  • Jan 23, 2007
  • #3
Here is a good diagram......................
 

manystangs

Member
Aug 6, 2004
67
0
6
Overland Park, KS
Jan 23, 2007
#4
  • Jan 23, 2007
  • #4
I remember on a Fox, I had that problem and it was caused by the Vanity mirror light staying on due to a broken visor. I know it sounds wierd but it was the culprit!
 

Igofaster13

Member
Mar 9, 2006
170
3
19
San Diego
Jan 23, 2007
#5
  • Jan 23, 2007
  • #5
Another....... I got to start working on it now, Will report back later today. Please help if you can think of anything. And where is the Voltage Regulator located? Thanks
 

Igofaster13

Member
Mar 9, 2006
170
3
19
San Diego
Jan 23, 2007
#6
  • Jan 23, 2007
  • #6
Ok, I tested voltage at that connector/voltage regulator, and all three pins were at 12 V. Testing the wiring harness terminal "I" now.
 

Igofaster13

Member
Mar 9, 2006
170
3
19
San Diego
Jan 23, 2007
#7
  • Jan 23, 2007
  • #7
Still have no clue is to whats wrong, Maybe faulty alternator somehow?
 

mo_dingo

20+ Year Stangneter
Aug 26, 2003
3,031
2
58
Tucson, AZ
Jan 23, 2007
#8
  • Jan 23, 2007
  • #8
The voltage at the back of the alternator (big wire) should be ~14.4V+ DC at initial startup, and drop to ~13.6 after a few minutes. If the voltage is less than 12.6 then the alternator needs to be rebuilt/replaced.
Scott
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
33
129
Jan 23, 2007
#9
  • Jan 23, 2007
  • #9
Scott's right-on.

Do keep on with your I wire testing since that's the turn-on for the alt. If it's open, the battery light shouldnt light up when you turn the key to run (while all the idiot lights come on and go out).

BTW, that's the most I've ever seen someone post to help themselves before.

Good luck.
 
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