Alternator problem

2003 MERCURY MARQUIS
130,799 MILES • V8 • AUTOMATIC
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JEFF BARR
  • MEMBER
  • 1 POST
The light green and red wire has no power going to it. It will not charge the battery from the alternator. how do I fix it?
Aug 20, 2019 at 8:13 AM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.
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BMDOUBLE
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 1,139 POSTS
I've included the pinpoint test procedure for the charging system. If you replace the alternator make sure it is the best quality one that you can get because the aftermarket world is having major issues getting it right!
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Aug 20, 2019 at 8:55 AM
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SCGRANTURISMO
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 4,897 POSTS
Hello,

In the diagrams down below I have included the charging system wiring diagram, connector end views, and factory diagnostic troubleshooting guide for the charging system not outputting power for you. Please go through these guides and get back to us with what you are able to find out.

Thanks,
Alex
2CarPros

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Aug 20, 2019 at 9:02 AM
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SCGRANTURISMO
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 4,897 POSTS
Hello again,

I thought that this link down below might be beneficial to you as well in helping track down your vehicle's problem.

https://www.2carpros.com/articles/how-to-check-wiring

Again, please keep us posted to how everything is progressing or how it turns out.

Thanks,
Alex
2CarPros
Aug 26, 2019 at 1:43 AM