minininja2121

Hello everyone.

so I bought a 2007 mustang GT and when I'm driving around my voltage goes way up(seems to be relative to rpms). It tells me to check my charging system and the battery light comes on. In addition to this my battery has started draining over night, but it holds a charge if I take the battery out. could this be caused by a bad voltage regulator?

Any help would be greatly appreciated.
-Jason

Glenn

Welcome to TMS. I would start by going to autozone and have them test your charging system. They can test the battery and alt for free. Does your battery at full charge have 13.5 volts or so?

minininja2121

last I checked it was at 12.76v after the battery was taken out for about 7 hours. And it was at 13.16v when I first took it out.

stupidgenius36

Do what Glenn said, and have a parts store check the charging system. It sounds to me like the alternator is at fault.

I've had a similar issue with voltage spikes at a specific RPM, which was caused by a faulty alternator.

minininja2121

Had my charging system check and it was in fact a bad VR. Got a new alternator and will let you guys know if that's fixes everything once I install it later today.

Thank you all for your help and speedy responses.
-Jason

Cavero

How up is way up? Definitely sounds like a voltage regulator to me. Unfortunately it's not a serviceable component separate from the alternator. If you replace it, get the 3 phase alternator for 2010 GTs. It's going to be much more reliable than the single phase that came in the 05-09

minininja2121

Well I finished up installing my new alternator and everything is good sofar

Thank you all for your input,
-Jason

Scarpi

My battery also got drained because the cd player was doing the same thing. The battery I had in the car was one month old from Ford. I took it back to my dealer and they gave me a new battery at no charge. I put it in and all has been fine for the last few months. I still don't know why the cd player was doing that. I haven't played cds in that thing in years. I was thankful that my dealer gave me a free replacment. The cd player has not repeated the problem.

Cavero

Nice, which alternator did you get?

m05fastbackGT

The OP's battery issues had nothing to do with the d@mn shaker CD player.. CD changers do not cause irregular voltage spikes while the car is being driven and then drain the battery from sitting overnight..

The shaker 500/1000 will only go through the process of cycling when the battery is nearly completely discharged and not before then.. As other's have previous posted including the OP, his battery issues were caused by a faulty alternator/voltage regulator, not the CD changer.. For those who store their cars for prolonged periods of time, what usually causes the batteries to drain is the K.A.M (aka) keep alive memory, faulty alternator/voltage regulators and active alarm systems.. The best solution is run a battery tender/trickle charger and don't arm the incline sensor of the active alarm system while in storage, otherwise disconnect the battery altogether..

m05fastbackGT

How do you know ? Simple, read the latest posts in the thread submitted by the other posters and by the OP.. That's how !

m05fastbackGT

If you had been paying attention by reading his latest posts, you would've already known the reason, as it was his voltage regulator that went bad and has since replaced the alternator.. So perhaps if you weren't so d@mn ignorant in the first place, I wouldn't have a reason for being a grouch towards you to begin with

m05fastbackGT

Yeah ! No kidding it's a common problem, which is exactly the reason I went through 3 batteries in my first S197 before you were even old enough to drive.. Therefore I know from personal experience what it's like to go through.. Just do a thread search on dead/drained batteries and you'll see for yourself just how many threads I've either started up or posted on during the past 11 years on this forum.. As for your CD player draining your battery is concerned, as I mentioned earlier, the shaker 500/1000 will only cycle when the battery is nearly completely discharged, as your car's keep alive memory is set up to require a certain amount of amps/voltage to remain active, otherwise if it drops below the minimum required amount, it will automatically begin the process of shutting down thus killing the battery.. The CD changer itself will not cycle on a fully charged or even a semi charged battery, unless there is either a short in one of the CD changer power amps or if the power button itself isn't manually turned off prior to shutting off the car's ignition.. However 99% of the time, it's the P.O.S motorcraft batteries that are at fault which is the main reason most people switch to either Interstate or Optima batteries that don't crap out and actually last up to 5 years just as a battery should in the first place..
Also as mentioned earlier, if you don't run your car for long periods at a time, the best solution is either run a battery tender or disconnect the battery altogether.. That being said, the CD changer once again had nothing to do with draining the OP's battery, it was his car's voltage regulator that crapped out in which he's since replaced with a new alternator..

m05fastbackGT

The reason why your CD player hasn't repeated the problem is because your replacement battery isn't a defective P.O.S unlike your original battery that crapped out only after one month..

Scarpi

Thanks for the info. Makes sense.

m05fastbackGT

I went through 2 motorcraft batteries that crapped out in less than 6 months on my first S197 that was factory ordered/delivered back in Feb of 2005.. It took a third replacement from my local dealership before finally getting a motorcraft battery that actually lasted 3+years.. Therefore anyone who tries to blame the CD changer for draining their motorcraft batteries are full of sh*t, as the CD changer doesn't even go through the cycle of searching for CD's until the battery is nearly completely discharged as the ECM's keep alive memory is set up to automatically kill power to the battery if there isn't enough voltage to keep it running.. Unless there's a short in one of the CD changer's power amps or if the power button itself isn't manually turned off prior to shutting off the car's ignition, those are the only possible scenarios connected to the CD changer that could possibly end up draining the car's battery, otherwise count on it being the P.O.S motorcraft batteries themselves 99% of the time..

Calimari1609

Mine started with the "Check charging system" light and battery indicator. troubleshot and it deemed the alt was bad. So i replaced it. 2 months and same initial indications. Now the "Traction Control off" lights up and the ammeter pegs high while it is on.
Last night, the right brake light came on after turning car off. I have no right turn signals, no side marker lights on any corner
Checked wire harness from tail light through to SJB. Opened SJB and see no incdication of water damage. Carpet is not wet.
Found water under rear seat, but it is a conv. So i am not too surprised.
Please help

Calimari1609

Ford states the sjb is no longer available.
Does anbody know of a rebuilder/repair shop for these?
since these are model specific, I am having a hard time finding a 2005 V6 conv box. Also, I have checked all over and took the pcb out of the box and there is no evidence of water in the sjb.
Any help would be appreciated.