2017 Mustang GT won’t start. No power at all.

[Jackhammer]

Hi Guys,

I am trying to figure out what went wrong with my Mustang.
I have a 2017 Mustang GT with about 5,000 miles.
I don’t drive it that much and it’s parked in my garage with a battery tender hooked up.
It never goes out in the winter and my garage is heated.
The last time I drove it was about a month ago and everything was fine.
Last night the wife and I wanted to go for a ride so we went out in the garage, unplugged the battery tender and got in the car. All was normal.
I pushed in the clutch, hit the start button and I heard a loud click and all the dash lights went off.
The car would start, wouldn’t crank and there was no power at all.
I checked the battery and the meter shows it’s at 12.7 volts.
The weird thing is, when I reconnect the battery, the throttle body is clicking and it sound like fuel pump try’s to start and then no power at all again
The little slash lights in the headlights are on too and won’t go off until you disconnect the battery.
Any help or suggestions would be greatly appreciated because I have no idea what happened.
I thought maybe the battery might have shorted or maybe the PCM failed.
No idea.

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[Fetlock]

Hi Guys,

I am trying to figure out what went wrong with my Mustang.
I have a 2017 Mustang GT with about 5,000 miles.
I don’t drive it that much and it’s parked in my garage with a battery tender hooked up.
It never goes out in the winter and my garage is heated.
The last time I drove it was about a month ago and everything was fine.
Last night the wife and I wanted to go for a ride so we went out in the garage, unplugged the battery tender and got in the car. All was normal.
I pushed in the clutch, hit the start button and I heard a loud click and all the dash lights went off.
The car would start, wouldn’t crank and there was no power at all.
I checked the battery and the meter shows it’s at 12.7 volts.
The weird thing is, when I reconnect the battery, the throttle body is clicking and it sound like fuel pump try’s to start and then no power at all again
The little slash lights in the headlights are on too and won’t go off until you disconnect the battery.
Any help or suggestions would be greatly appreciated because I have no idea what happened.
I thought maybe the battery might have shorted or maybe the PCM failed.
No idea.

Starter solenoid fuse or relay? Just a guess.

 

[Xzavior1818]

Starter solenoid fuse or relay? Just a guess.

My buddys battery in his car (non mustang) showed 12.8 volts but it still ended up being the battery for why the car didn't start. Id say pull the battery and get it tested at the local parts store.. Its free and a good start.

If its the battery I recommend a North STAR AGM or Oddessy AGM battery. Good luck!

 

[FruityJudy]

You need to load test the battery for amperage. Volts dont crank cars. You could have a bad cell or 2

 

[Torched10]

My buddys battery in his car (non mustang) showed 12.8 volts but it still ended up being the battery for why the car didn't start. Id say pull the battery and get it tested at the local parts store.. Its free and a good start.

If its the battery I recommend a North STAR AGM or Oddessy AGM battery. Good luck!

I'd jump start it first.sounds like battery.do you have ford pass app.if your in low battery it'll tell you.ser if you can remote start it from app.

 

[NightmareMoon]

I concur its probably just the battery. 3 years is about all they last, esp the factory batteries seem to fail like clockwork after 3 years. Reminds me I need to change mine out in 6 months /before/ if fails the next time.

 

[15GTCA]

I would disconnect and clean all the ground connections. Your car is old enough to need them cleaned. Then check the battery.

 

[Rapid Red]

3 years old car rarely driven, battery. Trickle charger can bring a good battery to life.

Old battery, cell sulfation, not a chance. The 12.5 is a surface charge, has nothing to do with cranking power.

You must drive the car to keep it operating...

 

[Elp_jc]

If you have a battery Tender, then that's your problem. If you want to leave a charger connected permanently, you need a 'smart' one. Those BT+ cook the batteries when left connected. I use an Optimate6, but there're several other models, as well as other brands, like C-Tek, etc. Sounds like the battery to me, but jump it and you'd know. Good luck.

 

[Jackhammer]

Thank you for all the replies.
I pulled the battery out if my Fiesta ST and put into the Mustang GT and it started right up.
I’ll get a new one at the ford dealership tomorrow.
I get a pretty big discount there through my friends body shop.
Thank you for helping.
I was freaking out because I started reading about PCM’s going bad and stuff and didn’t know what to do.
Yes. I do use the Battery Tender brand trickle charger. The same I type use on my Harley’s and sport bikes.
I have used them for the last 20 years on the bikes and never even had to replace a battery.
What do you recommend for a car then?
Optimate6 or C-Tek?

 

[Twin Turbo]

Glad you confirmed it was just the battery. For reference, I keep my S197 on a CTEK battery tender that maintains a charge (but doesn't overcharge). Several years ago I had exactly the same issue as you.....disconnected the tender and she wouldn't fire into life. A new battery resolved it and, touch wood, I've not experienced that again. So, even when on a maintenance tender, a battery can still go bad.

 

[Rapid Red]

Thank you for all the replies.
I pulled the battery out if my Fiesta ST and put into the Mustang GT and it started right up.
I’ll get a new one at the ford dealership tomorrow.
I get a pretty big discount there through my friends body shop.
Thank you for helping.
I was freaking out because I started reading about PCM’s going bad and stuff and didn’t know what to do.
Yes. I do use the Battery Tender brand trickle charger. The same I type use on my Harley’s and sport bikes.
I have used them for the last 20 years on the bikes and never even had to replace a battery.
What do you recommend for a car then?
Optimate6 or C-Tek?

Same here on the battery tender, in fact I have 2 on the 32 & 34, using them for 20 years now.

So they are good to go, all that happened with yours was the Mustang needs to be driven more often ........... incentive LOL

PCM's are stable, and last thing on the troubleshooting list. All the nutty flickering, odd ball things happening. Where because the surface charge you read. Was just enough to power up the PCM, and have it run the cars system checks.

Simply stated, the PCM got confused, with the power fluctuating as the load increased. And the power dropping because of the load. The PCM tried its very best to respond to the signals being returned, and shit happens.

Good to here you had a happy ending..

Cheers

 

[Torched10]

Glad you confirmed it was just the battery. For reference, I keep my S197 on a CTEK battery tender that maintains a charge (but doesn't overcharge). Several years ago I had exactly the same issue as you.....disconnected the tender and she wouldn't fire into life. A new battery resolved it and, touch wood, I've not experienced that again. So, even when on a maintenance tender, a battery can still go bad.

On my 14 shelby I had battery replaced 3 in 3 years under bumper to bumper warranty.id drive it at least every2 weeks,but only 6000 miles in 3 years before I sold it for my gt pp1 vert.they gave me 49k on trade,and 52 for new gt.funny,I didn't want to spend that much,but the dealer said I had to buy a car that was more than 49.all they had were 2 pp1 cars and a Bullitt,so I bought the ruby red metallic.so far so good.1200 miles on it in a year and battery is holding up.

 

[Deleted member 35786]

Hi Guys,

I am trying to figure out what went wrong with my Mustang.
I have a 2017 Mustang GT with about 5,000 miles.
I don’t drive it that much and it’s parked in my garage with a battery tender hooked up.
It never goes out in the winter and my garage is heated.
The last time I drove it was about a month ago and everything was fine.
Last night the wife and I wanted to go for a ride so we went out in the garage, unplugged the battery tender and got in the car. All was normal.
I pushed in the clutch, hit the start button and I heard a loud click and all the dash lights went off.
The car would start, wouldn’t crank and there was no power at all.
I checked the battery and the meter shows it’s at 12.7 volts.
The weird thing is, when I reconnect the battery, the throttle body is clicking and it sound like fuel pump try’s to start and then no power at all again
The little slash lights in the headlights are on too and won’t go off until you disconnect the battery.
Any help or suggestions would be greatly appreciated because I have no idea what happened.
I thought maybe the battery might have shorted or maybe the PCM failed.
No idea.

Stop letting it be a garage queen and drive that thing more!

 

[Rapid Red]

On my 14 shelby I had battery replaced 3 in 3 years under bumper to bumper warranty.id drive it at least every2 weeks,but only 6000 miles in 3 years before I sold it for my gt pp1 vert.they gave me 49k on trade,and 52 for new gt.funny,I didn't want to spend that much,but the dealer said I had to buy a car that was more than 49.all they had were 2 pp1 cars and a Bullitt,so I bought the ruby red metallic.so far so good.1200 miles on it in a year and battery is holding up.

Must have some thing to do with the colors you picked. I say stick with the ruby red metallic, for longer battery life.

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