P1246 I REPLACE SEVERAL ALTERNATORS NEW BATTERY ...

  • Tiny
  • autotech53
  • 2002 Ford Focus
  • 135,000 miles

P1246 I replace several alternators, new battery checked wiring from alt to pcm alternator is charging but light comes on and also reflash pcm please help

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Tuesday, October 16th, 2012 AT 5:33 PM

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  • Tiny
  • evolve960
  • Expert
  • 49 posts

P1246 - Alternator Load Input Failed

Possible causes GEN-MON circuit short to GND.
GEN-MON circuit short to B+.
GEN-MON circuit open.
GEN-COM circuit short to GND.
GEN-COM circuit short to B+.
GEN-COM circuit open.
ILC circuit short to GND.
ILC circuit short to B+.
ILC circuit open.
Battery-sense circuit open.
Generator drive mechanism.
Damaged generator/regulator assembly.
Damaged PCM.

P1246 Description:
The PCM monitors generator load from the generator/regulator in the form of frequency. The frequency range is determined by the temperature of the voltage regulator, where 97% indicates full load, and below 6% indicates no load.

Verify the battery voltage is 14.5 volts.
Verify the generator/regulator has the correct part number.

I did find a TSB about this issue for the 2000-2001 but not on the 2002 model year it is possible you may actually have a 2001 but made mid year and classified as a 2002
Could you please provide me with the build date ( MO/YR) from the drivers door sticker.

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Tuesday, October 16th, 2012 AT 5:44 PM
  • Tiny
  • autotech53
  • Member

Sorry I said 02 ford its 2000 ford

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Tuesday, October 16th, 2012 AT 6:04 PM
  • Tiny
  • evolve960
  • Expert
  • 49 posts

There was, a TSB about replacing wire harnes's used on these vehicles, however no recall. A PCM reflash probably wasnt neccesary, as it may actually be causing the issue.

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Tuesday, October 16th, 2012 AT 6:16 PM
  • Tiny
  • evolve960
  • Expert
  • 49 posts

If you have replaced this a few time where are the parts comming from? If you can get part numbers throw them in the post here. If there salvage that maybe the correct tree we need to bark up so to speak.

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Tuesday, October 16th, 2012 AT 6:17 PM
  • Tiny
  • autotech53
  • Member

Two junk yark, three auto zone and three adavance auto parts an one napa auto parts. These alternators only charge to 14.1 volts and assey on 13.65 volts only

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Tuesday, October 16th, 2012 AT 6:26 PM
  • Tiny
  • autotech53
  • Member

Did u get my message yesterday

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Wednesday, October 17th, 2012 AT 6:54 PM
  • Tiny
  • evolve960
  • Expert
  • 49 posts

Sorry for the late reply, the original post was supposed to be 13.5 volts. Typo on my part. Has the PCM been looked into these are known for causing a no charge condition were it does not cycle the alt like it should

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Tuesday, October 23rd, 2012 AT 10:56 PM
  • Tiny
  • evolve960
  • Expert
  • 49 posts

If it is indeed charging the battery like it should. Then the issue is a wiring problem behind the dash somewhere causing the battery light to come on.

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Tuesday, October 23rd, 2012 AT 10:57 PM
  • Tiny
  • autotech53
  • Member

I took a 00 ford focus alternator, battery and pcm installed it in mine and it still dose not charge. I put all the parts back to this other ford focus and it charges 14.8 volts. I also put the three wires in back of alternator to pcm and still dose not charging.I have already spend 800 dollars and I dont know where to go next. I have been a auto tech for 30 years and I am stuck of what to do. Please help////////

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Friday, November 23rd, 2012 AT 7:59 PM

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