New alternator not charging

[Obi-Wan]

My neighbor has a '95 Windstar with the 3.8L V6. The alternator wasn't charging the battery, which caused the battery to die. On the advice of the genius at Jiffy-Lube, he bought a new battery yesterday, but of course that didn't help. I dug out my multimeter today and verified that the new battery had 12.2V, but the positive terminal on the alternator only measured about 11.8V. Tried replacing the regulator, but that didn't help. We put a "new" rebuilt alternator in for $140, ran the engine for about 20 seconds, and measured a steady 14.5V at the positive alternator terminal. We declared the operation a success, and I packed up my tools and went home.

Later this afternoon, after less than 30 minutes of driving around town, the battery had drained so low that the engine died just 3 blocks from home. After a quick jump start and a short drive home, I measured 11.5V on the battery. Turning the key just clicked the starter. We jump started it again to get the alternator turning, and with the other vehicle still connected via jumper cables, I measured just 12.2V at the alternator's positive terminal. The new alternator obviously had stopped charging again.

Any ideas what could be causing this? The alternator worked briefly when it was first installed, but obviously quit soon after. Is there something else in the vehicle that could cause the stator not to turn on? Where do the stator & field signals come from? The wires just disappear into a huge harness and I lost track of them.

We don't have a manual of any sort for this Windstar, and my neighbor's extremely short on cash, so he doesn't want to buy anything he doesn't have to (including a $140 alternator that doesn't fix the problem). He also really needs the vehicle to be running when he goes to work on Monday, so he didn't want to wait until the work week to take it to a mechanic and then pay outragous labor costs.

I'm a decent shade tree mechanic, but I mostly know Jeeps, and by this point, I'm at a loss without a service manual of some sort. Any help would be greatly appreciated!

[spanners]

Condolences

I'm in exactly the same boat. 98 Winstar 3.8, new battery and alternator but still the van dies.
My multimeter is a small analog type and might be the next purchase to add to the growing bill.
B+ post around 12 and A&I post at 12&1 volts approx.
With the battery being run the next step will be to find a charger I can borrow.

[Obi-Wan]

Well, after swapping in 2 rebuilt alternators, we finally hauled it into the dealership. Their first response was "your alternator is dead -- you need a new one." Well no duh. We insisted that that wasn't the root of the problem, and that they should look further. Eventually they found a fuse that was burn out (a tiny 15A fuse in the engine bay fuse block). Replacing that fuse solved the problem. Even the "dead" alternator sprang to life, which makes me wonder if the original alternator had any problems at all. :-(

What really confuses me is that the first "new" alternator we installed seemed to work just fine for at least a minute while we were testing it, so I assume that fuse must have blown sometime after that. I'm keeping my fingers crossed that this problem doesn't pop up again...

[DRW1000]

I was going to suggest that perhaps something was loading down the charging system. The higher the load the lower the voltage will be (within certain limits). The blown fuse seems to support that theory but of course after it blew the charging systems should have worked fine.

What was the fuse for? I don't see why a blown fuse should affect the charging system. As far as I know the charging system does not pass through a fuse.

[Obi-Wan]

Originally Posted by DRW1000

I was going to suggest that perhaps something was loading down the charging system.

No, there was no appreciable load on the system. I checked everything I could think of with my multimeter, but didn't find anything. The major cables were all in good shape, too.

Originally Posted by DRW1000

What was the fuse for? I don't see why a blown fuse should affect the charging system. As far as I know the charging system does not pass through a fuse.

That's what I thought, too, which is why I didn't bother checking the fuses during my own diagnosis. The Chiltons manual didn't reference any fuses in its description of the charging system. The fuse was a little 15A one in slot "T" of the engine bay fuse block. The Chiltons manual lists this slot as unused. We don't have an owners manual for the car. The label on the under-side of the fuse block lid assigns a letter to each fuse slot, but doesn't say what they're for.

This turned out to be one heck of an expensive ordeal thanks to a little 59-cent fuse. Hopefully others will learn from our experience.

[easternshorelady]

I have a 95 Windstar with the same exact problem you seem to have had. I checked all the fuses and could not find the blown fuse you referred to (In the Engine Bay Fuse Block (where is the fuse block located) in Slot T. I have put 3 alternators on the vehicle and a new battery plus cables. I had the alternator re-tested and they stated that the alternator and the battery are good. My van continues to have the same problem you were experiencing?? Do you have any further help or suggestions??

[beuthling]

The fuse box in the engine is mounted beside the batery. Just pop the top of black box and there is your fuses and relays. Just look at your manual for the van--

[12Ounce]

I'm learning something here... the Windstar alternator has some sort of external alternator regulator protection fuse....?
I just took a look at a '96 glove box manual on-line at : http://www.genuineflmservice.com/default.asp?page=E4
.
Apparently that's what the T fuse is ... at least, on some models.