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Dangerous sudden complete loss of electronics

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Boardman
#1
Hello all, hoping someone on here can help identify what happened with my car yesterday. I’ve got a 2014 Fiesta ST. Currently has 54k miles, and I’m the original owner. The car has no prior history for electronics faults (besides the typical Sync module sometimes getting stuck in a loop which kills the battery if you don’t catch it, but that has only happened twice, and you can tell when it happens because the Sync screen becomes unresponsive to touch). The car has also been driven cross country a few times with zero issues, and has a brand new battery as of December of last year.

I was driving from my apartment in Phoenix to Los Angeles, and near Indio I noticed what appeared like all of my lights on the dashboard came on. About 2 seconds later, everything electronic went out - And I mean everything. All the lights, the odometer, the climate control, the tach and speedometer, and (most concerningly), the electronic power steering and electronic throttle body. The Sync system stayed on, but went black with a loading bar and displayed a message saying something like “Battery saver mode…” or something like that. The car stayed running, but without a working throttle body, I couldn’t do anything. This was very dangerous, as I had no way to even signal or put on my four ways to indicate there was an issue. Fortunately, I was near an exit ramp, and coasted up and to a safe place on the side of the road.

I attempted to turn the car off, and found I couldn’t. Every time I pressed the button to cut power, nothing would happen. Right before I was going to just stall it out, the button worked. As soon as it shut off, the odometer came back on like normal when you turn the car off. I turned the car back on, and everything powered up fine, but there were lots of lights on the dash. Then, 2 seconds later, everything died again. Again, the car stayed running and fought me turning it off. I tried this a couple more times, and not getting anywhere, decided to try one last thing. I reached into the engine bay, wiggled and twisted the positive battery cable, and worked it off of the terminal. I let it sit for a couple minutes, then reconnected it. When I fired the car up again, a bunch of lights came on. CEL (not flashing), I think a trans fault light, ABS, airbag, etc.. I figured these were false alarms, shut the car down, fired it back up, and they all went away. I drove around town for a couple minutes, then got back on the highway. I resumed by drive, got to LA, then turned around and drove back. I never encountered a single issue the rest of my drive.

Now, I should mention that a few weeks back, on my drive home from work, I noticed a couple lights came on my dashboard for a very brief moment. I saw the ABS and at least one other light I couldn’t make out briefly flash, but then go away. Nothing else occurred, but I thought that was very odd. I have no idea how many lights actually came on, because again, it was very brief. I just figured it was an odd glitch or something or that I was just seeing things.

Has anyone seen anything like this before, or does anyone have any idea what I can try to test? The car is out of warranty, and I know the dealer would be practically worthless here anyways, as intermittent issues like this are almost impossible to find. I’m just very, very hopeful someone has seen this before and figured out what was wrong, as this is a seriously scary thing to have happen, especially if it happened somewhere at night with a limited shoulder and I had no way to even turn my flashers on..
 


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Location
Sacramento
#2
Not exactly the same - but similarities worth noting...

I have a 2014 - 50k mi and original battery. I changed my interior lights to LEDs. Start the car and electrical flips out on dash, sync cycling, engine wouldn't turn over and then the electronics locked with my headlights staying on now with no response from the ignition.

Popped the fuse box under the hood, changed fuse 35 & relay 3. This solved my issue. Replacing my battery next.

Best of luck on the fix, youve got this!


Sent from my Pixel 2 using Tapatalk
 


TyphoonFiST

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Rich-fizzield
#3
Battery could be on it's way out....get it checked or look at the maintenance free Eye....what color is it? It should be green...if not give it a charge....if no change in eye color...fill with electrolyte and check it again....still no change....time to replace. Battery life is 3-5 years on a lead acid. You are on borrowed time my fellow FiSTer.

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Last edited:
OP
Z
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Boardman
Thread Starter #4
Thanks for the replies. The battery was replaced a couple months ago at the dealer, but I can have them check it again. I'll also look into that fuse/relay set and see if I notice anything blown.
 


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113
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Location
Santa Cruz, CA, USA
#6
These symptoms are very similar to my experience with another car, and it was the alternator dying. I replaced the alternator and all was good.
I can second that, On my move out from phoenix to Norcal my alternator died in my honda. I was 10 miles away so I limped it to my new place with no electronics or power steering. Started with an abs light then every couple miles a new light until it all lit up then no more electronics. New alternator fixed it right up.
 


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Location
Decatur
#7
I'm wondering if it would be worth putting a digital voltmeter on a main bus somewhere. Voltage level so crucial with all the electronics these days.
 


OP
Z
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Boardman
Thread Starter #8
I can second that, On my move out from phoenix to Norcal my alternator died in my honda. I was 10 miles away so I limped it to my new place with no electronics or power steering. Started with an abs light then every couple miles a new light until it all lit up then no more electronics. New alternator fixed it right up.
Alternator is a very good thought, but unless the FiST is very different (which it might be, that's why I'm here asking :)) than other cars, usually when an alt dies the car will run off of battery power for some time, right? I'd expect to see a charge system fault, lights dimming, and the car gradually draining the battery, but this was like a light switch being flipped.

Has anyone had an alt die in one of these cars? Is what happened to me typical?
 


kivnul

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#9
It also could not hurt to check various vehicle grounding points.
 


OP
Z
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Boardman
Thread Starter #11
It also could not hurt to check various vehicle grounding points.
Is there a good list or wiring diagram showing the main grounds? To lose all electric power, I'd think it must be one of the main ones.

Are there any codes set?
No, no codes set at all unfortunately.

To add to this thread, it happened to me twice today on my way home. Not a full shut down, but I felt the engine lose throttle and then the tach and speedo shut off, then everything came right back within a second. It didn't act up at all earlier this morning or the last 2 days, so I don't know what to even think at this point.

I also called a few local dealers to ask if they've encountered it before. The most valuable bit of info they gave me was "Oh my gosh, that's definitely not normal!".. Also had one "tech advisor" tell me it was probably just the auto start-stop feature. Amazing. They offered to scan it for me for a couple hundred dollar fee, but what's the point? There's no codes.

I also did some playing around in the engine bay. The car runs fine with the battery unplugged, so it's not a loose connection there and I'm almost certain not an alternator. I looked around for any obvious loose wires or corrosion on grounds and didn't see anything that stood out. I'm just bumping this thread with an update because I'm praying someone here has seen this before, because if not, pretty sure I'm screwed.

And a very sincere thanks to everyone who has posted up suggestions so far, I really do appreciate the help.
 


PunkST

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Menasha
#12
Check the battery cable connections down by the starter and the grounds within the engine bay. The positive is one big long cable instead of two separate ones in modern cars. I had an odd issue witj my svt focus after 10 years. The cables were rotten and needed replacing. Im wondering if yours are totally baked. There is also that big fuse on the positive side on the battery terminal.
 


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Location
North Branford
#13
Sounds like you have something going on with the voltage out of range, or possibly a ground issue somewhere. Which would sort of be one and the same.

Remember that alternators can fail in both directions, just because it's charging/keeping the car running doesn't mean much if it's pushing out 20v or something because of a failing regulator.
 


OP
Z
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Boardman
Thread Starter #14
Check the battery cable connections down by the starter and the grounds within the engine bay. The positive is one big long cable instead of two separate ones in modern cars. I had an odd issue witj my svt focus after 10 years. The cables were rotten and needed replacing. Im wondering if yours are totally baked. There is also that big fuse on the positive side on the battery terminal.
Just did a pretty good inspection, and they all look good, at least from what I can see. Plus I tested what would happen if I just unhooked the battery (trying to recreate it) and nothing happened, the car just kept on running off the alt.

Sounds like you have something going on with the voltage out of range, or possibly a ground issue somewhere. Which would sort of be one and the same.

Remember that alternators can fail in both directions, just because it's charging/keeping the car running doesn't mean much if it's pushing out 20v or something because of a failing regulator.
Would the alternator trip some kind of warning or blow a fuse if it was pushing out voltage that high? I'm also suspecting a ground, but the hardest part for me to explain is if it is a ground, why would it be "fixed" by unhooking and then reconnecting the battery? That part just makes no sense to me. And why would it let the car start with all computers on behaving normally, and then shut everything down 2 seconds later again and again? It just doesn't make sense to me. I'm not saying you're wrong, this is just such a weird thing.

Also, more info to note: I found another member on this site who experienced this exact same issue with his car. He got lucky, and apparently his issue went away on it's own, but he stated that the dealer checked over his car in depth and found zero issues with the charging system, and were basically useless... Really disappointing to hear, but kind of what I expected out of something so intermittent.
 


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181
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Location
North Branford
#15
A warning or chime is doubtful, maybe there's one on the fiesta, I don't know for certain. Look in your owner's manual, maybe it says something about it. Don't read too far into that number, it's not meant to be a literal value. You want to be charging at somewhere around the 13-14.5v range. If you put a voltmeter on it and see it bouncing pretty far all over the place, there's probably something going on there.

There's most likely a fuse or a circuit breaker in the charging circuit somewhere, but that would be reactive to current instead of voltage. Some other people mentioned loose/corroded connections. That's a good place to start. I've seen more than a few older fords that were pretty sensitive to dirty battery terminals. Like the others mentioned, the battery should be in a good state of tune as well. It's not really good to be running anything modern off of just the alt, with no battery in the circuit.

Anyways, weird electrical things like that are notoriously difficult to diagnose, unless you can observe some specific condition to repeat the issue consistently. Hopefully it's just a one off and you'll never see it again. If it starts becoming a frequent occurrence, then it's time to dig deeper.

There's always this...
View: https://www.youtube.com/watch?v=t2F1rFmyQmY
 




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