I have a 2000 Ford Excursion Limited, 230k, v10

for about the past 8 months have had a problem keeping the battery charged. Have taken it in to the local mechanic a few times and always says battery and charge system are fine, but if you leave it sit for a few days battery is dead

so in the process of changing the battery we noticed when you pull the ground terminal that there is a spark if you touch the terminal to the post.

So we put the terminal back on and drove it home, then I disconnected the ground at home, got a meter and began pulling fuses to see which circuit the draw was coming from. on most it would start at -1.30 ish and then drop quickly to -.34 and hold there.

relay #2 dropped to -.20 (battery saver relay)
fuse 1 dropped to -.18 (radio, Secondary Fusing for Audio Options)
fuse 14 dropped to -.18 (Dome Lamp, Cargo Lamp, Courtesy Lamps,
Running boards, Power mirrors, Vanity Mirrors
Map Lamps, Underhood Lamps, Glove Box Lamp
Power Windows (Delayed Accessory))

fuse 15 dropped to -.01 (Stop Lamp Switch (Logic), PATS, GEM)

so we pull the fuse 15 while its sitting, and replace it to drive, as the fuse shuts off all interior lights, power windows and the vehicle wont shift into gear with it out.

Any Ideas what it might be, or how to check further to find the dead short thats killing my battery?

much thanks

 

You have to wait at least half an hour for all modules to go to "sleep" before you do any testing. There's no dead short, just something that is staying on.

 

ok, if terminal disconnected, still have to wait half an hour, even if interior lights out? so what is staying on?

what is drawing power?

check it for draw with hood up and terminal off after half an hour?

 

For a 2000 the GEM will stay on at least 30 min after the key is turned off.

Battery—Drain Testing

Check for current drains on the battery in excess of 50 milliamps with all the electrical accessories off and the vehicle at rest. Current drains can be tested with the following procedure.

WARNING:
Do not attempt this test on a lead-acid battery that has recently been recharged. Explosive gases can cause personal injury.

CAUTION:
To prevent damage to the meter, do not crank the engine or operate accessories that draw more than 10A.

Note:
Many computers draw 10 mA or more continuously.

Note:
Use an in-line ammeter between the battery positive or negative post and its respective cable.

Note:
Typically, a drain of approximately one amp can be attributed to an engine compartment lamp, glove compartment lamp, or luggage compartment lamp staying on continually. Other component failures or wiring shorts may be located by selectively pulling fuses to pinpoint the location of the current drain. When the current drain is found, the meter reading will fall to an acceptable level. If the drain is still not located after checking all the fuses, it may be due to the generator.

Note:
To accurately test the drain on a battery, an in-line digital ampmeter must be used. Using a test lamp or voltmeter is not an accurate method due to the number of electronic modules.

1. Make sure engine compartment and interior fuse panels are accessible without turning on interior and underhood lights.

2. Drive the vehicle at least 5 minutes and over 30 mph to turn on and exercise vehicle systems.

3. Allow vehicle to sit with the key off for at least 1 hour to allow modules to time out/power down.

4. Connect a jumper wire between negative battery cable and negative battery post to prevent modules from resetting and to catch capacitive drains.

5. Disconnect negative battery cable from post without breaking the connection of the jumper wire.

6. Note:
It is very important that continuity is not broken between the battery and the negative cable when connecting meter. If this happens, the entire procedure must be repeated.

Connect the Alternator, Regulator, Battery and Starter Tester (ARBST) between negative battery cable and post. The meter must be capable of reading milliamps and should have a 10 amp capability.

7. Note:
If the meter settings need to be switched or the test leads need to be moved to another jack, the jumper wire must be reinstalled to avoid breaking continuity.

Remove the jumper wire.

8. Note:
AMP draw. Draw will vary from vehicle to vehicle depending on the equipment package. Compare to a comparable vehicle for reference.

No stock vehicle should have more than 50 MA draw.

9. If the draw is found to be excessive, pull fuses from the interior fuse panel one at a time and note current drop. Do not reinstall the fuses until you are finished testing.

10. If the draw is still excessive, then remove fuses from the engine compartment fuse panel one at a time and note current drop. Do not reinstall fuses until you are finished testing.

11. Check the wiring schematic in the wiring diagram for any circuits that run from the battery without passing through the engine compartment fuse box. Disconnect these circuits if the draw is still excessive.


Battery—Electronic Drains Which Shut Off When the Battery Cable is Disconnected

1. Repeat the steps of the battery drain testing.

2. Make sure all doors are closed and accessories are off. Without starting the engine, turn the ignition switch to RUN for a moment and then OFF. Wait a few minutes for the illuminated entry lamps to turn off if equipped.

3. Connect the ampmeter and read the amperage draw.

The current reading (current drain) should be less than 0.05 amp. If current drain exceeds 0.05 amp after a few minutes, and if this drain did not show in previous tests, the drain is most likely caused by a malfunctioning electronic component. As in previous tests, remove the fuses from the fuse junction panel one at a time to locate the problem circuit.

 

Ok, fabulous reply. I am unsure of what you mean by the jumper cable.

When I did my first testing I just waited and made sure interior lights were off. I am guessing the reason the jumper cable must be installed is the systems reset and does diagnostics etc anytime there is an off event with the electricity, thus continuity must be retained after its had the 30 min (1 hour to be safe) time to power down.

The meter I was using was a good electricity continuity tester, which had a 10 amp setting, and thats the setting I was using, but it was not inline, I would just use the pointers to make connection.

Sounds like I need to get one of those inline meters or take it into a shop that has one.

And inside first, then engine comp fuses, so accessing the inside ones without setting things off would be done with an open window? Sounds fun.

Have I got that about right?

Again, very much thanks.

Kent

 

Read 4-7 for the jumper. You need one of these, about $20 and up to $500+ .


Testing For Current Drain That Runs Down Car Battery - YouTube

 

Yes, thats what I used to test with. I am still unsure how you can use those pointy things to maintain continuous connection, I guess you tape them in place, then remove the jumper cable?

and does it make a differance if you do it on the ground side or the positive side? My positive side bolt wont unthread as the round thingy thats supposed to be attached to the positive terminal clamp that has the female threads just spins away and since its round and recessed a bit in the clamp its really hard to grab onto it.

 

Everytime you disconnect and connect the battery it's like turning the key on. The purpose of the jumper cable is to prevent the modules from waking up. You can skip the jumpers but you will have to wait at least 30min for the modules to power down. You can use the neg terminal.

 

1. Hey, much thanks for the directions, took a while to get the jumper cables, we live north of civilization so had to wait for the next trip down, but did the testing as recommended, and battery draw after an hour was .02 amps, so not enough to kill a good battery in a day or two.

Replaced the battery under Ford warranty, cost $50, was a year past free replacement.

Problem solved.

Thanks again

Kent