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Electrical issue starting car

gatornek

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Hi all. Figured I'd be proactive with this issue, as my BS sits in downstairs at my work parking lot, idling by itself.

When I went down for lunch, and I pressed the start button, I saw a flicker of electricity immediately run through the cabin, and then immediately off, within a split second. No engine cranking whatsoever.

I'm like "geez" ... "What happened? Did I accidentally leave a light on". But even leaving a bulb light on for a few hours, would still theoretically give me more juice then what I just experienced.

Alright fine, whip out my AstroAI car jumper. It's at "94", but that should be good enough. I hook it up, and it gives me E6, which means that the jumper doesn't feel it has enough juice to jump the car. The boost button won't turn on. Really strange. Alright fine, let me take back up to my office, and I charged it up to 100.

Went back down to the car. Still got the E6 when I placed the jumper to the battery, but this time it did allow me to enter "boost" mode. Once "boost" mode was activated, I did hear the electrical whine sound through the engine. I went in to the cabin, saw that the accessories were on, and proceeded to start the car.

"Problem over", I thought. Not quite. Here's the weird part, as soon as I REMOVED the jumper from the battery, the car died again. A little bit of panic ran over me, because this usually indicates a more serious problem ... maybe even the alternator.

So here's where I started to rack my mind. And my thoughts began with the fact I just recently swapped out the FOMOCO battery for an Inter-State from Costco, as after 3 years in South Florida, the FOMOCO battery did die on me once. This was back in June maybe. However, what I did not do, was reset the battery monitoring system. Every once in a while, a message would come up on the console that the battery needed maintenance, but since I knew I had a brand new battery in there, I simply pressed ok.

So now I'm like "Gee, I wonder if this has anything to do with not doing that procedure". So I put my jumper back on to try the reset procedure. Correct me if wrong:

Close doors
Turn on accessory power only
Within 10 seconds,
Flash high beam five times,
depress brake pedal 3 times

However, I did not see any type of 'change' on the console.

Went back under the hood. This time, as I came up front, before I even lifted the hood, I can hear electrical whine and engagement under the hood.....then I jumped the car again. Something tells me I might not have even needed the jumper, as I could hear the radio and accessory power was obviously running in the cabin. Like I said, that's a brand new Interstate in there. This time when I removed the jumper, the car stayed running.

I left it running downstairs, since I'd really like to get home without a tow, or asking my wife to come get me.

Ideas? The thing that really trips me out, as how the car immediately died after I removed the jumper the first time. It really felt like the alternator wasn't doing what it was supposed to be doing? Is my hunch correct? Is this related to me not resetting the system after swapping the battery, you think? I can't handle dealing with a bad alternator right now.

I'll update the thread once I go downstairs, get in my car, and hopefully get home.
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nkromer

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Sounds interesting. I have swapped my battery and did not do a reset with no issue. However, your procedure seems correct.

The only thing I can say is that there was a recall on the 2021 battery and Ford replaced mine at no cost. Of course, this was after I replaced the original with an autozone battery when the FoMoCo battery died. Ford still swapped it though, so now I am back to the FoMoCo battery.

If you have a volt meter and know how to properly use it, take a reading of your battery voltage, meter set to read DC volts, while the car is not running. Then start the car and take a second reading. The voltage should increase on the second reading if your alternator is properly charging your battery.

Make sure you know how to use a meter and do NOT have it on the current/amp setting. You will open the circuit on your meter.
Ford Bronco Sport Electrical issue starting car 1000006939
 
Last edited:

Whpony96

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Some questions for you:

1. Did you replace the FoMoCo battery with a lead acid or AGM battery? The Bronco Sport requires a AGM battery.

2. Did you get the same CCA (Cold Cranking Amps) as the original?

3. Did you just go buy the battery yourself and install it or did Interstate come out to the parking lot and install it for you?

4. Did you reset the BMS (Battery Management System) right after installing the new battery? This must be done immediately after battery replacement.
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