Battery light coming on?

2000 FORD WINDSTAR

3,747,284 MILES • 3.8L • V6 • 2WD • AUTOMATIC

DANIELSHEA100

MEMBER
3 POSTS

So, the battery light on my minivan was coming on when I stopped for a period and the dash lights were dimming and brightening. So, I had it tested, and they said that the battery was good, and the alternator checked out good, but the voltage was going up and down, so I went ahead and changed the alternator because they said that that is a sign of it going bad. Then I drove it and it came on again when I stopped for a period, what else do I need to check is there a fuse somewhere? Please help minivan is my fiancé and it is her work vehicle she cleans houses for a living.

Apr 4, 2023 at 1:21 AM

STRAILER

✓Experienced Mechanic
55,256 POSTS

It sounds like one of the fusible links has one out or is weak, I would use this guide to check the connections and I have included the alternator wiring diagrams so you can see how the system works and which wires to test.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Check out the images (below). Please let us know what happens.

Image (Click to enlarge)

Professional Diagram for 2CarPros Members
Click here to log in and view diagram.

Apr 4, 2023 at 3:38 AM

DANIELSHEA100

MEMBER
3 POSTS

I talked to a good friend of mine that works as a mechanic attic mechanic shop, and he said the easiest and cheapest way to fix it would be to run a 10-gauge wire straight from the alternator to the positive side of the battery. He said that will bypass the fusible links if one is bad. what do you think? I want a second opinion.

Apr 4, 2023 at 10:06 PM

STRAILER

✓Experienced Mechanic
55,256 POSTS

Yep, that will work, also test the remaining fusible it is easy to do. Let me know what happens.

Apr 6, 2023 at 4:01 AM

DANIELSHEA100

MEMBER
3 POSTS

I put the 10 gauge wire straight from the alternator to the positive side of the battery and that did not work battery light still came on.

Apr 6, 2023 at 4:05 AM

STRAILER

✓Experienced Mechanic
55,256 POSTS

Did you check the fusible links? You may have a bad PCM or instrument cluster. I would do a CAN scan; you can get a CAN scanner (Controller Area Network) from Amazon.

Here is a video to show you how:

https://youtu.be/u-4syLc-ifQ

and

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Here is one for about $99.00 if you need it:

https://amzn.to/3ZixY4v

Apr 8, 2023 at 6:09 AM

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