20-amp alternator fuse blows when turn the key

Hi,

I'm not sure what the differences are with the replacement alternator, but your vehicle may not be designed to work with it.

Now, I attached the wiring schematic below of the charging system, and I don't see anywhere there is a yellow wire. Please review the schematic and let me know.

Next, the idea that you see 30v is nearly impossible. Are you certain the setting on the multimeter was set correctly (AC vs DC)?

Take a look at the schematic below and let me know which wire you are referring to.

Also, let me know if you have other questions.

Take care.

Joe

See pics below. Note: I had to cut the schematic in half to make it readable for you. I did overlap them so you can follow from one to the next.

Thanks for your reply Joe. The multimeter was set on dc volts. I took an accurate reading of the battery at 13v then turned the key on and took the reading on the wire at 29v and today 24v. I'll try and send pics. It will show the wire i am testing o. Correct me if I'm wrong but the diagram you sent me is for a generator? I have a 2000 f150 6cylndr 4.2liter.
Thanks

Hi,

For some reason, they still identify them as a generator in the manual. I have no idea why. LOL

Do the wire colors look correct in the schematic I provided? As far as the fuse, it has to be shorted at some point when you turn the key on. Have you inspected the wiring?

Do me a favor. Remove the fuse from the box. Check the pins in the box for continuity to ground so we can see if that is the issue.

Let me know.

Joe