So I had the same problem alot of the S4 guys are having... the stock 70A alternator is barely enough to keep up with the stock system never mind a car with fans, stereo, amplifiers, etc....

So after doing some searching, I discovered some people on the forum have done Taurus alternator swaps... it's a 130A alternator, and because there are so many Taurus's, they're pretty cheap. The swaps that I did find done here seemed too complicated, they were making crazy brackets to make the alternator fit.

I made a trip down the local junkyard and picked up a mint alt out of a 96 Taurus, 3.0 OHV engine. My research tells me a 3.8 alt will also work. Looking at the alt, I found a way to mount it without having to make the brackets.

The Taurus uses a serpentine pulley, and the pulley on the stock S4 alt doesn't fit onto the shaft of the Taurus alternator. Rather than drilling out the stock pulley, I made a trip down to a local alternator shop and picked up a brand new pulley slightly larger than stock (so I don't over-rev the alternator) that fit perfectly on the shaft of the Taurus alt.

The Taurus alt has two ears on it, one small and one big. I had to grind a little off of the small ear to get the pulley alignment just right. When grinding it, you have to make sure you keep the surface flat, so you dont throw the pulley alignment out on the vertical plane.





Once that was done, I realized that the other ear was too high for the stock adjuster bracket. I unbolted the adjust bracket, and made a small extension for it, drilling an extra hole in the oem bracket so the extension couldn't rotate, and three holes in a 1/4 piece of steel, bolted the two together and put it back on the car:





The belt was pretty simple- I need a belt 1" longer than the OEM belt.

Once I had the alternator in, it was a simple matter of wiring it up. The Taurus uses a system a lot like the FC. The main cable to the battery was upgraded to a 4GA, hooked up, run through a 150A circuit breaker, and connected to B+.



There are two other plugs on the Taurus alt, a single wire and a three wire. The single wire connects to the middle pin on the three wire, labeled "S". The two remaining wires are "A" (Yellow/White) and "I" (Green/Red). "A" Needs to be wired into constant power (I wired the original alt power wire to this, and "I" Goes to switched power, Black/White wire on the stock S4 alt harness.

Once that was done, I got to work on upgrading the ground wires on the car- I grounded the engine to the body using a tab on the back of the Taurus alternator, and an unused hole on the shock tower:





I grounded the body directly to the battery, connecting to an unused hole near the coil. You can see it (blue cable) in the picture below. You can also see the power cable running down to the circuit breaker, and and the new batter cables. The two small wires hooked up to the battery go directly to my voltage gauge:

Started it up, and boom, 13.86 V at idle




Raised the RPM a bit, to 1500, and was just over 14 V:




Hope all this info helps somebody!

-Dirk

 

NICE write up!..should be archived,as it is so simple.

 

Are the pics huge for everyone?

 

how much would you charge to throw together a kit?

 

A kit? There really isn't much to this swap... a pulley, a piece of steel, a longer belt, and of course the alternator...

 

I wish that fat-assed alternator would fit under my TMIC. Unfortunately my FD alt barely fits and IIRC the Taurus alt is larger in every way.

 

Hm, my S4 alt is dying and I was going to either get another one or switch to an S5 alt but I can see this as being a cheap fix. Can you use any Taurus alt or are there only specific years? My voltage is sometimes dropping to 12V in the car and my alt is only providing around 48A. I can see it dying by the end of the year so I'm either going to buy a truck earlier than I thought and put my car in storage until next summer or I'm going to have to replace my alt. Also, am I going to have to buy the 150A breaker? I don't think I've seen anything like it under my hood.

 

Nice work - this is now added to the list!

 

Right in time, Dirk! (Needing a newer/better alternator anyway.) Will do. Great write-up!

A question, though... So, 4GA wire from battery to 150A breaker to B+, and also 4GA wire for ground?

 

nice

 

Welcome to the 130 Amp Taurus Alternator Club.

Nicely done. Your method is easier to duplicate. If I do another one on an FC, I will do it your way.

Couple of things: The circuit breaker serves no purpose- the under hood main fuse box is more than sufficient. Negative on the circuit breaker is that it is a failure point in the system and that now you have 2 unprotected 'hot' lugs that offer the possibility of creating a short while working on anything nearby.

And there is no need for a ground wire on the Alt. It is already grounded at multiple points. More grounds are not more better.

 

My alt just failed.... hmmm.... the taurus alternator is too big to fit under the TMIC, it seems (if i take JustJeff's word for it.) Does anyone know of any other similar alternators that would work as a substitute / upgrade from the s4?

 

So, really it is as easy as Taurus alternator, grinding, different pulley, longer belt, and extension?

 

can you please post what pulley you used? and the part number for the belt? i think that would complete the little details needed =) (i also wonder if a dual belt pulley exists for it )

 

Yes.

Maybe the OP could measure the final thickness of the ground 'ear' to give some guideline to how much to grind.

 

What's the point of the spacer on the bolt now?

 

Now THAT'S awesome! I had a quick search from auto zone of the part numbers for the alternator and found:
14497 or AL-485.

 

Can anyone post how they wired this to the stock alternator wire harness? What does he mean by "original alt power wire on the stock harness"?

 

any news on the pulley part number or the belt length? i just got the alternator and harness yesterday from pick-a-part

 

based on my research i think this one will fit. I will double check in the morning.

Taurus V-belt pulley

 

I bought the belt just the other day... I totally forgot what size the guy said. If you have them look up the belt for your FC, and inform them that you want one an inch longer, they'll hook you up.

So far my Taurus alternator has worked great!

 

That pulley wasn't the one. Does anyone happen to know where they got their pulley from? I read somewhere late 80's subies have a dual belt pulley that fits but when i was at the junkyard all i found was serpentine belt pulleys.

 

this has help me greatly thank you!!!! chwkrx7

 

Reviving the thread here. So I'm having 2 problems with this alt. I ground the ear down and it barely reaches the second spot on the pulleys which I thought was fine. The pulleys were off so I modified the alternator a little more so it was dead on. Now I keep blowing belts and I can't figure out why. It squeaks a little and then boom it's done. Does the belt need to be on the first spot on the water pump and crank?
Second problem is I blew 2 main fuses during spirited driving. I can only find a 120amp fuse that will work in the stock fuse block. Has anyone else used something different or what could I do to re-route the power?

Cheers,
Trevor

 

I also did the Swap had to trim 5/16th off of alternator lined up on point. Found 150amp fuse at a local car audio shop (nice gold) all 4guage wire. No prob yet but i do notice 16v charge at idle. Ok? No Ok? Whatever it keaps up with electric fan and other electronics.