No output from alternator

[Conflict]

Advance says its a good alternator. It's got 12v coming in but nothing coming out. How can this be? It's an 01 crown vic.

 

[lil_Blue_Ford]

If it’s not putting out about 14.4 volts, then the alternator is bad. I don’t trust Advance with testing stuff, I had one of their batteries that died under warranty. I’m no noob, so I checked it, put it on my trickle charger overnight, tested it again, verified an internal short that was causing it to self-drain, left it overnight in the cold in the truck and took it to them to warranty after work the next day. They “tested” it three times and their “tester” said it was a good battery… I explained that it simply wasn’t possible as the battery had already froze into a block of ice (middle of winter). Took dragging their commercial manager out of his back office to confirm the battery was junk because it “tested” good.

Autozone also will test alternators and the like, I’d try getting some confirmation. I’d also inspect the wiring in the vehicle and check the main fuse under the hood.

 

[Shran]

If it tests good then my guess is you have a fuse or fusible link blown somewhere. Alternators need power in order to make power so you need 12v at the excitor terminal, if you don't have that then they will do nothing but spin.

If your battery is very low then it's possible that you will see way less than the normal ~14.x charging voltage until the battery recovers. I just dealt with this last week and the battery voltage read 13-13.2v for quite a while until it had ran long enough to charge the battery. Now all is good and it is steady at around 14.2v

See this:

Ford Crown Victoria Alternator Wiring Diagrams

 

[Conflict]

Yea I verified power coming in on the #3 pin. So the alternator is being told to send out power. The battery is at 12.5 and the alternator output just reads the same while running. So it's doing nothing and there's no other conclusion than a bad alternator. Advance must be wrong. Right?

 

[lil_Blue_Ford]

Yea I verified power coming in on the #3 pin. So the alternator is being told to send out power. The battery is at 12.5 and the alternator output just reads the same while running. So it's doing nothing and there's no other conclusion than a bad alternator. Advance must be wrong. Right?

That sounds like it’s getting signal but not turning on to me…