Odd charging issue. Help please.

Discussion in '2005+ Mustang GT 4.6L Tech' started by Blue Roads, Mar 11, 2019.

  1. Blue Roads

    Blue Roads Junior Member

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    I'm putting the backstory on this in case anyone has seen anything that may tie these things together. I've been patient, understanding that a 10 year old car is going to have issues, but I'm now at the point where I seriously regret buying it.

    I've got a 2008 GT, automatic, stock.

    Jan 24, 2019, I bought the car from Carmax.

    Feb 2, just over a week later, the check engine light comes on. It's code P0155, O2 sensor. I take it back to Carmax. They put an O2 sensor in it, claim it was a bad one and they needed a Ford OEM sensor, which still doesn't fix it, so they send it to the Ford dealership, who claims they put the wrong O2 sensor in it, which still doesn't fix the CEL. They conclude that the PCM needs to be replaced, and it takes them until March 1 to do all this diagnosis, approve the new PCM, and have Ford put it in the car. I pick up the car on March 1.

    March 2, ONE DAY LATER, I'm driving home and the battery gauge (I'm guessing it's a volt meter) starts to drop, and a block from my house the gauge turns red since it hits bottom and odd lights are coming on in the gauges, the ABS light and traction control light, along with the battery light. The radio was off but came on and reset itself, and the CD changer started clicking. I turned off the headlights and pulled the parking brake while I was sitting at the red light, and that brought the gauge back up where it should be. I got home and checked the battery voltage with the car off, 11.5V. It sitll managed to start the car. With the car running, 11.0V. I charge the battery and on Monday morning, March 4, I take it back to Carmax. They replace the alternator and battery, and I picked it up yesterday, March 8.

    Today, ONE DAY LATER, while getting on the highway, I gave it a good bit of throttle and the ABS and traction control lights came on in the gauges again. They turned back off when I let off the throttle. I noticed it continuing to do this, and found that anything over 2000 RPM would cause those lights to come on along with the battery light, and would peg the battery meter all the way to full. Later in the evening I was driving and it happened consistently over 2000 RPM, and if it stayed there for more than a few seconds, the interior lights would turn off, but my headlights would remain lit. Once the RPM dropped, the interior lights would come back on. The fog lights would also turn off when this happened, and the radio has reset itself again.

    I've heard about the 2010 alternators being a better 3-phase design, but I'm not sure what got put into this car for a replacement alternator. I'm thinking it's the original spec single phase alternator, if I read other posts correctly as to how it came from the factory.

    I've attached pictures of the well under the passenger side windshield cowl, and the SJB. Looks to be OK from what I can see.

    Any thoughts? Has anyone experienced stuff like this? I'm taking it back to the dealer on Monday morning.

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  2. msvela448

    msvela448 forum member

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  3. brford

    brford Junior Member

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    You should check the two cables that are attached via connectors with bolts to the left (passenger) side of the radiator support. I'd suggest removing the bolts, making sure that the cables are well connected to the interlock washer that the bolt goes through. Make sure that washer is making good contact to the radiator support. These cables ground the charging system. In the event of a front accident they break off or disconnect and disable the electrical system.
     
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  4. Blue Roads

    Blue Roads Junior Member

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    Thanks for the info!

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  5. Blue Roads

    Blue Roads Junior Member

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    Thanks again for the referral to Department of Boost. If the dealer will approve it and it won't hurt my warranty and extended service, I'm going to get one of their alternators and have it installed since it's getting done under warranty.
     
  6. msvela448

    msvela448 forum member

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    Good deal... Those are really nice alternators, and the price is good too.

    I hope it solves your problems.

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  7. 406guy

    406guy Junior Member

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    Do you know the part number of the Denso plug and play replacement? I am also interested in this.
     
  8. Blue Roads

    Blue Roads Junior Member

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    I went to the Department of Boost Facebook page and got the owner Jason's email there. I emailed him and he responded right away. Very helpful. It turned out I didn't need to buy one from him, as the dealer replaced my alternator under warranty. As soon as I need an upgrade I'll be contacting Jason again.
     
  9. msvela448

    msvela448 forum member

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    The Motorcraft GL950 is the stock Denso unit Ford Part # 9R3Z10346B. This one is with the clutched pulley for manual cars. The one without the clutched pulley for automatic cars is the GL960 (9R3Z10346D).

    But the ones from Department of Boost are upgraded and powder coated. He will also do 8-rib versions if you need that.

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  10. msvela448

    msvela448 forum member

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    Did the new alternator fix the issue?

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  11. Blue Roads

    Blue Roads Junior Member

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    So far it has been good. I'll keep you posted.