2012 Edge Strange electrical problem, how do I diagnose it?

[Mike Scir]

My neighbor has a 2012 Edge that kills the battery pretty quickly, I think it goes from fully charged to unable to crank the engine in one or two days. (there is a bit of a language barrier but we usually manage). He replaced the battery 3 weeks ago but no change. He took it to a shop that tested the alternator and they said it was good. 

 

Electrical problem history: 
First he said the interior light would not always go off when the driver side door was closed. 

Then he said an engine compartment fuse blew, I looked it up and it appears to be the #18 40A HVAC blower motor, it looks melted and fused. 

Then he mentioned that he heard a buzzing or clicking sound from the engine compartment fuse box and indicated where he thought the noise was coming from but I didn't find any bad fuses in the immediate area, also pulled several, including a black box that might be a relay, that didn't prevent the next symptom from happening. 

 

This is the interesting part: 

I got a voltmeter and without the + cable attached the battery measures 11.4V. With the + cable attached it oscillates between roughly 5.3V and 4.1V about once per second. 

Does these symptoms make any sense to anyone? While to me, on the surface they appear unrelated (door interior light, HVAC fuse, oscillating battery drain) maybe this all makes sense to someone. 

He said there were zero problems that he was aware of when he purchased the vehicle. 

 

Note: The owners are low income and said if I can simply disconnect problematic circuits but the car will still run normally ans safely and pass smog, they'd be happy with that, if the repair would be costly (more than say $200). 

 

Thanks in Advance,
MIke

Edited Tuesday at 04:40 AM by Mike Scir

[1004ron]

9 hours ago, Mike Scir said:

This is the interesting part: 

I got a voltmeter and without the + cable attached the battery measures 11.4V. With the + cable attached it oscillates between roughly 5.3V and 4.1V about once per second. 

Battery appears to be past its useful life.

 

Charge it and then take it to a place like Autozone for them to do a health check on it, free of charge.

 

.

Edited Tuesday at 11:07 AM by 1004ron

[Mike Scir]

Thanks, I'll do that. The battery is only 3 weeks old. Is it possible the short was so bad it killed the battery? 

[Mike Scir]

We replaced the battery, my mistake, it was 3 months old (not 3 wks). The new battery measures 12.6V with nothing connected, and 12.2V with the terminals connected. Is that a normal voltage drop for a vehicle where everything is turned off? 

When started the alternator charged at I think over 14V. We're headed to Auto Zone to see if their ODBC sensor says anything interesting. 

...

ODBC said it's not smog ready but there's no check engine light so it may be unrelated, they said run some cleaning fluid through it. That's a problem for another day. 
The keyfob remote stopped working, replacing its battery made no difference, so either the remote sender or the radio in the car is bad. 

...

How's this for a diagnostic procedure:

 - monitor the battery voltage while pulling one fuse or relay at a time to see where the current is going, battery voltage should rise when a current drain is removed. 

 - are there any fuses or relays I should avoid when doing this test, either under the hood or inside the vehicle? 
 

Any suggestions will be appreciated. 

Edited yesterday at 12:59 AM by Mike Scir

[1004ron]

Not too sure of what's written but it sounds like I was right, a dead battery.

 

While at Autozone have them put their battery tester on it which will display state of charge, CCA, Cranking Voltage and charging Voltage.

[1004ron]

Do a Google search for "how to find parasitic draw on car".

[Mike Scir]

The battery that went bad was purchased from Costco 3 months ago. It died pretty quickly. 
The new battery we installed today is the warranty replacement from Costco. 

I'll do the google search you recommended. Thanks. 

[1004ron]

It takes just one deep discharge to destroy a lead-acid battery, which a parasitic draw will do - thank goodness for Costco's good warranty cover, but they might not be so willing if the replacement is returned in a few days, so best disconnect the battery when the car is not in use until the parasitic draw is resolved.

[Mike Scir]

Thanks, I didn't know that. I have a clamp meter and will start pulling fuses tomorrow, we'll keep the battery disconnected from the vehicle (except for testing) until we find the problem. thank you. 

[1004ron]

Its only recent years that DC clamp meters became available - is yours one of the later models that's DC capable?

[Mike Scir]

My CM1000A (Harbor Freight) measures DC current, nice meter! I watched videos as you suggested, followed instructions, clamped the negative terminal connecting cables, with the remote 60' away and after the car had been left sitting for an hour it appears the computer successfully went to sleep, I pulled each fuse and relay in the engine compartment fuse box one at a time, the current draw oscillated between 2.2A and anywhere from 700mA to 20mA or so. 2.2A is a battery killer... and way above the normal range of 20-50mA as the video I watched stated. 

 

I wanted to do the same with the interior fuse box but I don't know how to defeat the switch that indicates the door is open, I didn't see any external switches anywhere in the frame by the door so the switch is probably internal in the door somewhere, opening the door wakes up the computer and turns on the courtesy light, I was seeing 9A draw at one point, I believe I can turn off the light with a switch but the video said to let the computer be in sleep mode or it will draw significantly more than sleep current. I think I'll pull the fuse for the door switch if I can find one for that, then I can do the inside fuse box.  

 

Thank you for telling me what to google, that made it a doable job. 

Edited 15 hours ago by Mike Scir

[Mike Scir]

Possible good news, Google AI said this (below) I'll be looking into these two tomorrow. 

A fluctuating, cyclical drain that jumps between 2.2A and 50mA every minute indicates that a computer module is attempting to go to sleep, but a faulty component or network signal is repeatedly waking it back up. When it wakes up, it boots the module (drawing ~2.2 Amps), fails to stay awake, drops back to baseline sleep (50mA), and then immediately cycles again. [1]

Instead of pulling fuses one by one—which can accidentally wake up other networks and ruin your data—the most efficient strategy is to look for the two most notorious culprits on the 2012 Ford Edge that create this exact cyclical 2-Amp pattern. [1, 2]

Prime Suspect 1: The Shifter "Park" Switch (Most Common)

Ford Edges of this generation have a highly documented flaw where a small microswitch inside the center console shifter assembly fails.
<snip>

Prime Suspect 2: The SYNC Infotainment Accessory Delay Relay

The APIM (Accessory Protocol Interface Module) or the main radio screen can hang up during its shutdown process. It will pull about 2 Amps trying to run a background cycle or failing to turn off its internal hard drive/Bluetooth seeker. [1, 2]

 

[1004ron]

My next step would be to use Forsan to check for codes.

[Mike Scir]

The cable's a bit expensive, the owner is low income, I'll try pulling the two fuses the AI suggests and see what happens before spending money. Thanks for telling me about Forscan, I never heard of it and it is a pretty powerful program. 

[1004ron]

A basic fairly cheap OBDII dongle and the free Forscan Lite is all that's needed to reliably scan for codes.

 

Some places like Autozone have scan tools that can reliably read all Ford codes, but its hit and miss.