95 town car Cartier, 4.6 L engine. Battery Light came on. Battery was dead so I replaced the battery. Battery light still on, Had the alternator checked, bad, replaced the alternator with a new one. Battery light still on, Checked and found the alternator was not putting out. Pulled alternator, had it checked, it is good, reinstalled alternator. Battery light still on, I have 12 volts at the 2 pins of the 3 pin alternator plug with engine running. Battery light STILL ON! Replaced the Fusible links. . . Battery light STILL ON! Ohmed wires from battery to alternator, from alternator middle pin of 3 to single pin, all good. BATTERY LIGHT STILL ON! HELP!
Simple question . . .
At idle, how many volts do you measure at the positive and negative battery terminals?
With no loads
12 volts from the new battery with the engine running at any speed. Same volts with the engine off. Same at the alternator output with engine running or not. (remove positive battery terminal with engine running and it dies immediately.)
The battery is clearly not getting charged
Hard as it is to believe, it’s possible you’ve gotten a string of bad alternators
I’ve seen it numerous times
A few months ago, at our shop we needed an alternator. The first 2 were bad. The 3rd was good. And these were straight from the Ford dealer!
Should be getting 14.1v when engine is running.
Check trhe fusable link from the Alternator to the battery. This is probably burnt out and a replacement will solve the charging issue.
He said he already replaced it
I really think he may have run into a string of bad remanned alternators
Sorry I guess I missed that part.
Pardon my ignorance, but I lack access to technical documents…
Did the '95 Town Car have a separate voltage regulator?
Yes it does have separate voltage regulator. Bingo!
Rockauto shows the alternator as having the regulator bolted to the back
But they also show a separate regulator, which presumably is mounted somewhere else
Which is correct?
All the alternators with the rear view have the regulator attached to the back. It appears identical to the regulator listed separately. If you look at the ninth & tenth listings (AL7521N & AL7525N) where a front view is shown you can see the regulator poking out on one but not on the other. I guess it all depends on whether oldgoatdjs replacement alternator included the regulator.
My 2 cents
The very first regulator listed separately is different than the rest. It appears to be an externally mounted unit
I suppose that is not correct for this application?
My schematics are a bit murky but for what it’s worth with no guarantee of accuracy, there are 2 diagrams for a 1995 Town Car.
One is for a model with the heated windshield and another for the model sans heated windshield.
It shows that both models use an integrated regulator with the alternator but the wiring is laid out completely different from one to the other. One is simpler and the other more complicated with a starter interrupt relay, alternator output control module, and heated windshield module thrown into the mix. There are also a number of fuses and links involved in all of this.
It needs to be known if this car has a heated windshield or not and I’m not being facetious but the odds are when this is cleared up the answer will be something much simpler than perceived.