Electrical issue starting car

[gatornek]

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]

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.

 

[Whpony96]

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.

 

[gatornek]

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.

1. I replaced it with an Interstate at Costco, as I have done for just about every car battery I've had for the last 20 years.
2. I didn't doublecheck anything as neither Costco nor Interstate have led me astray, but I surmise that this one is it. It's off their website. Looks like it has 760. Is that supposedly enough?

3. As I indicated in the OP ... No, I did not do the battery management reset. I'm hopeful that it is the source of the problem, but still skeptical.

 

[gatornek]

UPDATE:

Yesterday, I woke up and ran into the exact same problem as I did on Monday at lunch. Went through the exact same steps where I jumped it and as soon as I removed the jumper cables, the car died. I "fiddled" doing this a couple of times, until one time after the car died and I came around the front, I instantly heard an 'energizing' sound (like a relay) and I just knew that the car was good, and I was able to start it WITHOUT jumping. But then on the way to taking my kid to school, up came a DTC on the dash.

So, I immediately stopped fartin around and went to the dealership. Told them the story, and of course they seemed confused, just as I am or anyone reading this. They read the DTC, and I should've took a picture, but it was PCM electrical related.

I asked them to do the oil change, reset the battery system, and just generally check it out.

Got the Swamp Ape back in the afternoon, oil change done, reset done, no other problems found.

If it returns, I think I really have no other choice then to go with an exact OEM FOMOCO battery and forgo the Interstate. I mean, these are some really weird gremlins I'm chasing, and it usually is due to either the battery or ground.

 

[Dude]

You probably already did this but check the battery ground bolt on the drivers side fender under the hood - several owners reported that bolt is loose

and check the cables on the battery just to see if they are snug … some of the battery replacement shops employ goobers

 

[Dude]

1. I replaced it with an Interstate at Costco, .. this one is off their website. Looks like it has 760. Is that supposedly enough?

760 is good, you can also look at the top of the installed battery … it almost always shows the specs

It’s not unusual to get a defective battery, you can return to Costco and they likely will install a new one for free - the interstate is a good battery for Bronco Sport - many owners use them

These are specs for the motorcraft AGM, part number could be different today

AGM Battery:
Motorcraft BAGM-48H6-760
760 CCA Cold Cranking Amps
Dimensions: 10.94" L x 6.89" W x 7.48" H
Reserve Capacity: 120 minutes.
BCI Group Size 48
Weight: 47lbs

 

[Whpony96]

OK this is screaming to me a bad body ground or bad new battery.

(I only use Interstate batteries when the OEM fails.) Honestly I would go and swap the Interstate battery. It doesn't cost you anything and it will rule it out. One hard lesson in today's day and age is "Just because it's new, doesn't mean it's good." You would be shocked how many sensors I purchased from auto parts stores were bad right out of the box. I ONLY buy parts direct from Ford now. I won't even grab them from Amazon anymore due to the fakes out there. When you swap out the battery I would do the following listed below at the same time.


The Battery Ground Bolt shown in the picture is only grounded by the threads of the bolt. I would remove the bolt and sand off the paint from the contact surface that will make contact with the bolt. Then use a wire brush and clean off the threads of the bolt. Then add some dielectric grease to the surface you sanded and threads of the bolt to prevent corrosion before reinstalling the bolt. Do NOT add a washer when reinstalling, this will only decrease the contact surface between the bolt and the body. You are trying to achieve a solid connection.

 

[gatornek]

Update:

By the way, I'm just checking this thread now, for the first time.

No problems yesterday. I was thinking 'oh, it was the battery reset that the Ford tech "officially did" when I took it in"

This morning. Same thing. Completely dead with an instant fizz-out of the start button, after initial accessory power when I opened the door. Then, dead.

Now here's where a key piece of evidence now screamed before my eyes that gives credence to all you thinking there's a connection issue. As I placed the jumper on top of the battery and BEFORE I connected ANYTHING .... I heard the relay energize whine ... and I'm like 'hmmmmm..." go over to the driver seat and see the accessory power, try to start the car, but apparently it doesn't have enough juice to turn over, but its not completely dead.

I hook up my jumper .... I DON'T need to "Boost" it, and the car starts, and the car holds.

I'm trying to juggle school drop off and morning work while working this issue, but yeah ... Im going to check the ground, I'm going to doublecheck the tightness on the terminals of the battery, and apply some dialectric as was mentioned.

Question is that "battery terminal top bolt" on the positive terminal the only place it controls the tightness of the clamp? It looks like it has some side bolt, but I'm not 100 if the top bolt tightens it in some form.

OK this is screaming to me a bad body ground or bad new battery.

LOL. I agree. And that would be great if I can find it and nip it in the bud. More to come.

You wanna know the crazier thing, is that I just literally did my brake pads myself for the first time on Sunday, and somewhere in the back of my mind, I was hypothesizing that I somehow shorted the electrical connection in the rear for the auto brakes when I removed the calipers, and maybe that's what it was. The timing was just too mind bending! But obviousy completely unrelated.





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[gatornek]

Update:

Electrical gremlins are crazy sometimes. And they can leave symptoms and scenarios that have you chasing your tail when the answer is right in front of you. Now remember, that I changed this battery over 2 months ago. Changing a battery isn't difficult and I would've figured everything was copacetic since the car started and ran without a hitch, for weeks, until this error popped up on my dash while I was driving

Since the car had been running for weeks, my mind went to "Damn, I didn't do that battery reset procedure and its confusing the system". Pressed 'OK', and continued driving without a hitch. Kind of forgot about it, since the car was running fine, but it was always in the back of my head, that I just need to sit down, and do the d@m "procedure". That came to a head on Monday, when the car fizzed out for the first time.

so fast forward ...

Ground bolt was fine. No corrosion. Nice and tight. Both battery terminals felt like they were pretty tight. I mean, look at the pic. But that being said, I went ahead and TORQUED them down, It seems like the positive terminal bolt still had some turns left in it. I've never really had to TORQUE down battery connectors like that ..... but I am heavily leaning into the 'bad connection' hypothesis. I mean, it really sent my head for a spin, when I would hear the car energize, simply by lifting the hood or placing something on top of the battery.

So far so good since yesterday afternoon. For sure if something else rears its head, I will be taking the Interstate battery back.

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