Climate Control and Battery Drain

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Hi all,

I've had the Mountaineer in my sig for just over 2 years now with little to no problem. No reliability problems whatsoever.

When I bought it I could've sworn the PO told me he installed a new battery shortly before I purchased it. I did see that it's a Motorcraft battery, not sure of any other details as I've never had cause to remove the cover. Never had a cranking issue or even any slight sign that the battery was old or weak, even in very cold startups.

Fast forward to last week and my wife told me that the electronic climate control is set to "OFF" every time she gets in the vehicle to go somewhere, despite what it's set at when she shuts the car off. At first I don't think much of it (bad idea). And as she mentioned it a second and third time, I absent-mindedly think it might be a fuse on a memory circuit or something, did a bit of googling but then abandoned it (also bad idea).

We set out to leave for Pittsburgh the other afternoon after the car's been sitting most of the week and there's no crank. Barely enough power to keep the interior lights on. After a quick charge and boost from the charger it starts, runs and has no issues through a couple startups the rest of the night.

Next day, after sitting overnight, it cranks slow but after a short drive, it spins over and starts like normal. I'm still not worried at this point (jeez, am I dumb).

Finally, today, it barely starts, after sitting maybe 18 hours, as usual. I'm still thinking it should be ok after a drive. We drive to the fairgrounds to go to the fair, car seems to run fine. We go in for about an hour and a half, come back out for my wife to feed the baby. Start it to move to a closer spot , it cranks very slow but starts, and then park there for a while.

After sitting for maybe 10 - 15 minutes my wife is still taking care of baby, trying to get her calmed down, I have have her try it to see if it will start and I just get a clicking solenoid. After panicking and realizing how I should've started looking at it earlier in the week, I find someone to jump start us and we drive directly home.

Needless to say, my number one priority is to get this straightened out as soon as any parts stores open tomorrow. I will get my multi meter out to try to check for parasitic draws but will probably also get the battery tested.

Does sudden, serious depletion of a battery's capacity happen in short order like this? Or is it almost certainly a drain issue? ODBII scanner showed 13.0v - 14.0v at the ECU while running, lights on or off, regardless of load. It did drop to 8.0v on cranking over just after shutdown.

PS - Guys, pay attention to your wives, they don't say things just to say them.
 
Is probably a shorted cell in the battery, and sometimes that just happens.
What kind of warranty does the battery say it has? Those are carried at the ford dealers, maybe see if you can warranty it.

The Climate control thing; yeah, it is on a always-on circuit. The voltage is probably dropping enough during cranking to make it lose memory.
 
Take it to Napa, o'reilly, etc. and have them test the alternator. A shorted rectifier diode in closed mode will do exactly this, despite a solid battery (if a rectifier diode is shorted closed it will drain the battery while sitting idle, you can see the draw on the negative post but not find it in a fuse box test). It will also cause AC ripple voltage or enough voltage drop to cause the auto CC symptoms noted (as Colt45ws already said).

If you have a multimeter, what is the voltage across the terminals with the car running, at idle? If it is the 13.0V at idle, then your alternator is clearly shot (that is NOT an acceptable value - that is not how a "12V" system actually works). Your alternator should NEVER put out 13.0V charging volts. That means your electrics are running off the battery, not the engine.

Quote:
PS - Guys, pay attention to your wives, they don't say things just to say them.


That, my friend, is sound advice everyone should listen to. If "she" says, "I feel xx..." I get right on it. Saves me much later headaches. 2/10 times it is really nothing unusual, but 8/10 times it is a problem growing.
 
The scanguage voltmeter isnt accurate to voltage at the battery. Because its monitoring voltage in the car though all the thin wiring with other loads, its .5-1V lower than actual.
And yeah, it could be a shorted diode. Usually I notice it though as the interior lights can get flickery. Either way Oro is right, should probably have the alt checked just to be sure its not an issue.
 
A "hungry" battery at idle can drop it to 13.0 volts. The next test if you feel like testing is to park it with the neg terminal disconnected. But I already have the feels you need a battery.
 
You need to do troubleshooting.

The first thing to test when you suspect the battery is bad, do a load test.
If you don't have a load tester either get one, Harbor Freight usually have it on sale for about $15-$20.
Or take out the battery and bring it to a part store.

Battery can fail even if it is only less than a day of age so when PO said battery is new, it does not mean anything.
You can hope that it is good but nowadays, no parts are good until tested.
As it is, if a batter last 3 years, it is good.
Wonder why they only give 3 years warranty with most of the mfg?

If the battery are load tested good than you can start moving to the alternator and starter.
 
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I did some testing and will be going to AZ for their battery test following this post.

When I first went out, battery showed 12.3v key off and then proceeded to start fine. Running showed 14.2v at alternator, 14.1v at battery, good right?

After one or two more starts the battery was down below 11v and as I was probing around dropped all the way to 9v. Mind you this vehicle has been sitting for 12 hours.

I did try to test for parasitic draw, I set the multi-meter for 200mA and it showed .3 on the display. This doesn't mean 300ma, correct? I'm reading it as 30mA which should be in the acceptable range for key off draw.

Sounding like the battery to me as the behavior is so erratic.

Also, found that the battery is a 'Motorcraft Plus' dated 2/14 with only 18 months free replacement. Pro-rated charge would probably be rather high at this point.
 
Also, load test when the battery was around 11v showed that it dropped down to about 7v.
 
So now I had to put the charger on it for a few minutes to get it started to go to the store and it's showing like 15.8 to 16v at the battery and alternator.
 
Replace the battery already. You're jumping it to go everywhere. Your load test already showed it as bad. You've verified the alternator is charging. The voltage is dropping so low during cranking that your computers are loosing the memory, that is why climate control shuts off and resets.
15.8 to 16V at alternator because alternator is being commanded to full field due to a dead cell right off the start.
Also sounds like previous owner got the cheap motorcraft if it only has an 18 month warranty. Similar to the ACDelco advantage line. Generally junk after a couple years but you get what you pay for.

For vehicles I keep, I throw an Odyssey AGM in them. I have one thats 8 years old thats been in a few different vehicles. It still maxes out my load tester at 1000cca. It's rated for 1750 ca. I expect a 15-20 year lifespan.
 
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Battery has been replaced, Duralast Gold. So at least that's something I won't have to think about for 3 years.

I'm wondering if my multimeter isn't messed up as I had the leads in the position for mA and then put them on the battery terminals to check voltage. For this reason I thought maybe the 16v number was wrong.

Seems good so far, I also had the guy at AZ run a charging system test after the new battery was installed and it all checked out so that's encouraging.
 
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