Battery voltage drops to 5V with negative connected on a Ford Edge

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Righty Tighty

Righty Tighty

Blame it on the dog
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Hey all, I hope this is allowed since this isn't Mopar related, but I've been racking my brain on this for a while now. My girlfriend's car is an '08 Ford Edge that I think has a parasitic draw, but I can't find it.

With a fully charged battery, after a few days the car will be dead in the morning. I can jump start it and it starts right up, voltage goes from almost zero to 12-13V within seconds. The battery is new, and while it used to hold a charge after jumping it, now it will drain down within an hour. That being said, I think the battery may be toast since it has been drained too many times.

I can charge the battery, and the voltage between the posts is high 12s, but the second I connect the negative terminal, voltage drops by more than half.

I've tried a parasitic draw test by disconnecting the negative terminal and touching my meter's probes to the negative post and negative terminal, setting it to the amps setting, and removing each fuse one by one to see if the number drops to zero. I removed every fuse in the car, but never saw the amperage drop.

What am I missing here? Bad ground somewhere?
 
I had similar on my '05 Ram. Battery kept going dead. No parasitic draw issues while testing.
One morning I go out to the truck and the radio is playing. Truck is locked and key is in my hand. Open the driver door and the "key in ignition" chimes start up.
WTF??
Give it a smack under the wheel and it all stops. Took a video of this happening as it did this more than once.
Changed this and no more issues since..........
upload_2022-7-7_17-47-20.png
 
Did it do the same thing with the previous battery? You have another you can throw in real quick?
 
Alternator is new and has tested good twice by the auto parts store, and voltage holds close to 14 while the car is running.

Daves69 said:
I had similar on my '05 Ram. Battery kept going dead. No parasitic draw issues while testing.
One morning I go out to the truck and the radio is playing. Truck is locked and key is in my hand. Open the driver door and the "key in ignition" chimes start up.
WTF??
Give it a smack under the wheel and it all stops. Took a video of this happening as it did this more than once.
Changed this and no more issues since..........
View attachment 1715952702
Click to expand...
Is there a way to test the ignition switch?

crj1968 said:
Did it do the same thing with the previous battery? You have another you can throw in real quick?
Click to expand...
It did do the same thing with the previous battery, which is how we ended up with a new one. The old one got pretty tired after dying so many times. I'll see if I can find another battery to swap in.
 
What was the exact amperage draw amount (with key out of ignition, all doors closed, no accessories on, and waiting about 5 mins with amp meter in place) ?
 
Remove feed to starter and test with battery hooked up again. That's a straight shot with no fuse if you got a bad starter....
 
I think on an Edge the PCM is involved with charging.....I have a BMW that has some sort of smart charging system, battery registering nonsense.... hold on.

Same type of situation...
Interesting, this dudes alternator also tested good but was bad. Maybe you can't test them properly without the PCM being involved. ??

Charging system issues
 
Righty Tighty said:
Hey all, I hope this is allowed since this isn't Mopar related, but I've been racking my brain on this for a while now. My girlfriend's car is an '08 Ford Edge that I think has a parasitic draw, but I can't find it.

With a fully charged battery, after a few days the car will be dead in the morning. I can jump start it and it starts right up, voltage goes from almost zero to 12-13V within seconds. The battery is new, and while it used to hold a charge after jumping it, now it will drain down within an hour. That being said, I think the battery may be toast since it has been drained too many times.

I can charge the battery, and the voltage between the posts is high 12s, but the second I connect the negative terminal, voltage drops by more than half.

I've tried a parasitic draw test by disconnecting the negative terminal and touching my meter's probes to the negative post and negative terminal, setting it to the amps setting, and removing each fuse one by one to see if the number drops to zero. I removed every fuse in the car, but never saw the amperage drop.

What am I missing here? Bad ground somewhere?
Click to expand...
Leave the negative cable on the battery. Remove the positive cable and with a test light put one probe on the battery post and the other on the cable if the test light lights up there is a short, and finding that on a modern vehicle will be a nightmare to say the least.
 
The test lamp test posted above is a good start. I NEVER put a multimeter (in "current" or "amps" mode) in series with a battery until I have "judged" it with a test lamp, and if it lights bright, then use a stop lamp bulb. This gives you an idea how heavy the draw is. Many multimeters ARE NOT very well protected in the current mode, regardless of fuses.

Think about the stuff in your car that is "hot" with key removed. Alternator certainly, but nowadays, the PA transistors in the radio/ remote amp, dome circuit, cig lighter, and a few other things.
 
Dan the man said:
Leave the negative cable on the battery. Remove the positive cable and with a test light put one probe on the battery post and the other on the cable if the test light lights up there is a short, and finding that on a modern vehicle will be a nightmare to say the least.
Click to expand...
Just start unplugging stuff. PCM first. My 2012 Caravan starter was shot. We took it in and the Kragen tester said it was good. Well, I knew it wasn't so I bought the rebuilt and we put it on the tester and it tested good too but it actually shot out with some force, unlike the old one. Ill take it! Put it in and off to the races......
 
65wgn440 said:
What was the exact amperage draw amount (with key out of ignition, all doors closed, no accessories on, and waiting about 5 mins with amp meter in place) ?
Click to expand...
My meter was set on the 10 amp setting, and I got .12 initially, then it slowly dropped to .06. So 120mA and ending at 60mA. That doesn't seem like a big draw to me, but what has me scratching my head is the voltage drop, not necessarily the amp draw.

Another strange thing is that my meter, when set to milliamps, would read zero. I only saw any sort of draw when set to 10 amps.

crj1968 said:
I think on an Edge the PCM is involved with charging.....I have a BMW that has some sort of smart charging system, battery registering nonsense.... hold on.

Same type of situation...
Interesting, this dudes alternator also tested good but was bad. Maybe you can't test them properly without the PCM being involved. ??

Charging system issues
Click to expand...
Thanks, I've read a little about this car and have seen that the PCM is a common problem, but I didn't realize it was part of the charging system -- I thought it had more to do with the transmission.

Frank Mopar said:
correct. I guess I should have been more specific that the alt is the parasitic draw.
Click to expand...
Thanks for the clarification, I understand now. I also didn't realize that an alternator or starter could draw current like that, but thinking about it now, makes sense.

Thanks for all of the good suggestions, I'll be trying them tomorrow morning when I get off work.
 
In my opinion 60ma is "getting up there." I'd like to see say, half that much. I see "on the internet" that vehicles range up to 120ma. I don't know how in hell you can park a vehicle for long with that much draw

Maybe it's time for engineers to "rethink."
 
I disconnected the positive cable and touched the test lamp to the terminal and post, lit up like a Christmas tree. So I started disconnecting things one by one, starting with the alternator. No change, then the PCM and every other harness/electrical connection I could find. No change, the lamp still lights up. I couldn't get to the starter without disconnecting the coolant hoses, so we might just take it somewhere if that's how deep I'm gonna have to get.

Engine running I get 14.2 volts, engine off it's been holding 12.69 volts for 20 minutes. Man, I have no idea...
 
Righty Tighty said:
I disconnected the positive cable and touched the test lamp to the terminal and post, lit up like a Christmas tree. So I started disconnecting things one by one, starting with the alternator. No change, then the PCM and every other harness/electrical connection I could find. No change, the lamp still lights up. I couldn't get to the starter without disconnecting the coolant hoses, so we might just take it somewhere if that's how deep I'm gonna have to get.

Engine running I get 14.2 volts, engine off it's been holding 12.69 volts for 20 minutes. Man, I have no idea...
Click to expand...

So now it has fixed itself?
Makes me think PCM and it got reset when you unplugged....not that I can say I know how it works.
 
crj1968 said:
So now it has fixed itself?
Makes me think PCM and it got reset when you unplugged....not that I can say I know how it works.
Click to expand...
I guess it seems to be resolved for the time being?? That’s kinda what has been bugging us, because the car will start fine for days on end, and then one morning it’ll be dead.

So far, the voltage readings seem fine, so we will see what happens the next couple of days.
 
50 ma is standard acceptable draw amount. I have seen some of these newer batteries do some pretty strange stuff.
 
if you have those tiny fuses that can be probed while in-circuit, measure voltage across each fuse with everything hooked up. You should get really tiny voltages or zero. I've used this method with great results to find parasitic draw

Does kinda sound like a bad battery
 
Prior to taking the troubleshooting steps yesterday, I made sure the battery was fully charged and took it in for a test, tested good. We’ll see how it goes over the next few days, I’ll consider probing the fuses.
 
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