Electrical battery runs dead

LWood

New Member
Apr 4, 2020
5
0
1
60
Georgia USA
I have 12,7 volts across the terminals where you plug in the fuse. I have performed a dark test for amps. half 1/2 amp. I took out the GEM module and the generator power from the terminals on the bottom of the high power distribution box.
 
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08GT500

Active Member
Jul 12, 2018
780
111
53
Massachusetts
I have 12,7 volts across the terminals where you plug in the fuse. I have performed a dark test for amps. half 1/2 amp. I took out the GEM module and the generator power from the terminals on the bottom of the high power distribution box.
Hi,
I’d listed (2) tests (B & C) that may not be feasible at this point, we can work around them numerically, using your information posted..

0.5 Amp isn’t an overly large draw for these vehicles, > 1 Amp is more a concern. What amount of time does it take for your 100% charged battery to reach a discharged state? (Properly functioning charger verified ).
For clarity, you took a Series measurement with your VOM between the battery post and it’s removed terminal to acquire the 1/2 Amp (0.50) reading, as indicated?
A. Battery voltage sits at 12.7VDC across the battery terminals?
B) If the alternators charge measured with your VOM across the terminals is not between 13.3-13.8 volts, I’d have its output tested.
B1) What is the vehicle’s warm idle, Voltage across the terminals when idling?
Running underdrive pulleys?
Serpentine belt squeal?
B2) Have someone bring the RPM’s to 1,000 & hold, voltage across the terminals change?
B3) If yes, have the RPM’s brought up to 1,500...2,000, locate it’s peak VDC & @ what RPM.(?)
C) Bring the battery in for a load function test.
D) What battery Mfg & P/N# are you running, how old is it?
.E) Verify All Pos.& Neg. terminals in the charging system are clean, non corroded & solid. Use Noalox or another electrical connection grease. Replace any questionable connectors.
F) Running an aftermarket stereo head unit with a remote triggered Amp & Subwoofer(s), Factory?
G) An aftermarket alarm system installed (working or disconnected)? Factory?
H) Checked the dwell on your interior light, verify it turns off?
(I) Check your compartment lighting & ensure the lights are triggered off? Trunk, Hood, etc..
J) Did this issue start worsening over time, or suddenly? Drive the car daily, more of a weekend car, or seasonal..recently pull it out for the year?
If it occurred suddenly, any recent changes made to the car, mod’s?
Good luck!
-John
 

LWood

New Member
Apr 4, 2020
5
0
1
60
Georgia USA
Hi,
I’d listed (2) tests (B & C) that may not be feasible at this point, we can work around them numerically, using your information posted..

0.5 Amp isn’t an overly large draw for these vehicles, > 1 Amp is more a concern. What amount of time does it take for your 100% charged battery to reach a discharged state? (Properly functioning charger verified ).
For clarity, you took a Series measurement with your VOM between the battery post and it’s removed terminal to acquire the 1/2 Amp (0.50) reading, as indicated?
A. Battery voltage sits at 12.7VDC across the battery terminals?
B) If the alternators charge measured with your VOM across the terminals is not between 13.3-13.8 volts, I’d have its output tested.
B1) What is the vehicle’s warm idle, Voltage across the terminals when idling?
Running underdrive pulleys?
Serpentine belt squeal?
B2) Have someone bring the RPM’s to 1,000 & hold, voltage across the terminals change?
B3) If yes, have the RPM’s brought up to 1,500...2,000, locate it’s peak VDC & @ what RPM.(?)
C) Bring the battery in for a load function test.
D) What battery Mfg & P/N# are you running, how old is it?
.E) Verify All Pos.& Neg. terminals in the charging system are clean, non corroded & solid. Use Noalox or another electrical connection grease. Replace any questionable connectors.
F) Running an aftermarket stereo head unit with a remote triggered Amp & Subwoofer(s), Factory?
G) An aftermarket alarm system installed (working or disconnected)? Factory?
H) Checked the dwell on your interior light, verify it turns off?
(I) Check your compartment lighting & ensure the lights are triggered off? Trunk, Hood, etc..
J) Did this issue start worsening over time, or suddenly? Drive the car daily, more of a weekend car, or seasonal..recently pull it out for the year?
If it occurred suddenly, any recent changes made to the car, mod’s?
Good luck!
-John
Thank you for replying John. The alternator is charging fine. I find it odd that I can read voltage across the place a fuse would be. The high voltage distribution box. GEM fuse has voltage across the terminals where the fuse would be. This should not have a ground present at this location. I assume I have two problems one maybe, there is a short or defect on the distribution box. And beyond, I have a shorted circuit to ground. But the dark test does not confirm that. I removed ever fuse and relay and alternator and strait wires circuit. And nothing takes away this voltage from the GEM fuse base. Only removing the battery. I have totally removed the GEM mode and all fuses. I need to get under this distribution box. I may make a quick disconnect with a household light switch to make a kill switch. Until I actually can find it.
 

08GT500

Active Member
Jul 12, 2018
780
111
53
Massachusetts
Hi,
No problems, I’d misinterpreted. 12.7V across the circuits fuse holder that powers the GEM- yes?
How long does it take to flatten out your fully charged battery?
How much resistance was measured in a series connection between the battery terminal & the bafteey?
Have you run a continuity test from the pole on the fuse holder that’s not supposed to be grounded to the disconnected battery terminal?
The GEM may remain active for 20 minutes or more, additionall h - the fuse tie to ground that’s allowing you to read 12.7V across one terminal that should be live, one that should be dead without aby voltage,
Is this the 5A circuit as shown on the schematic in the manual?
Another thought Is If you’re reading into another component/circuit within the GEM, a circuit within, or a component that connects to ground through a resistance, giving you a false reading of voltage when you measured it.
You’d need to check the resistance from the “ground” side of that fuse terminal to the negative battery cable (while disconnected from the battery).
-John
 
Last edited:

LWood

New Member
Apr 4, 2020
5
0
1
60
Georgia USA
Hi,
No problems, I’d misinterpreted. 12.7V across the circuits fuse holder that powers the GEM- yes?
How long does it take to flatten out your fully charged battery?
How much resistance was measured in a series connection between the battery terminal & the bafteey?
Have you run a continuity test from the pole on the fuse holder that’s not supposed to be grounded to the disconnected battery terminal?
The GEM may remain active for 20 minutes or more, additionall h - the fuse tie to ground that’s allowing you to read 12.7V across one terminal that should be live, one that should be dead without aby voltage,
Is this the 5A circuit as shown on the schematic in the manual?
Another thought Is If you’re reading into another component/circuit within the GEM, that’s notreading a circuit within, or a component such as a bleeder resistor to ground thadmn
 

LWood

New Member
Apr 4, 2020
5
0
1
60
Georgia USA
I removed the GEM module, I am wondering does the ignition switch go on this circuit. I do not have a schematic for this so I am in the dark, but not afraid to dig it out.
So I should not see 12 vdc I do have a ground. I told you I did a dark test right? .48 amp. Within tolerance. I took a look at the emergency cut off switch to the fuel pump to see if it had a short to ground. Unplugged the fuel pump harness. No change yet. Gonna look into the trunk lite and if I have a hood lite. I have a brake light on my roll bar gonna check those too. Any ideas are welcome pleeze
 

08GT500

Active Member
Jul 12, 2018
780
111
53
Massachusetts
Hi,
Ignition switch triggers it. So, yes, if the switch is hanging up it’ll cause a draw. You really need the diagram, bro. Otherwise, sooner or later...you’re chasing your tail.
Need the diagram, know ones listed up here somewhere..:shrug: anyone..?
 

08GT500

Active Member
Jul 12, 2018
780
111
53
Massachusetts
I removed the GEM module, I am wondering does the ignition switch go on this circuit. I do not have a schematic for this so I am in the dark, but not afraid to dig it out.
So I should not see 12 vdc I do have a ground. I told you I did a dark test right? .48 amp. Within tolerance. I took a look at the emergency cut off switch to the fuel pump to see if it had a short to ground. Unplugged the fuel pump harness. No change yet. Gonna look into the trunk lite and if I have a hood lite. I have a brake light on my roll bar gonna check those too. Any ideas are welcome pleeze
Yes, noted you ran a dark test. That’s why I’d thought it looked reasonable, I don’t get really concerned until about an amp. Under a 1/2 amp draw is within manual spec’s. If that’s all that’s being drawn from your battery, then why is it depleting quickly- but how quickly is “quickly”?
How long does it take for a fully charged battery to go flat on you?
Best!
-John
 
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