I am having problems with my 2002 Ford Escape 3.0L.
My son was driving it on a road trip. He got about 110 miles away when it started acting up. Basically, it lost engine power. He could only do 55mph on the flats, and small hills slowed him down to about 45mph. He got turned around and made it to a rest stop about 60 miles from home. As he pulled in, the engine died. The dash lights had been varying from "Check Engine", "ABS", "Brakes". The engine was also very hot, and coolant was coming out the overflow. I met him about 2 hours later. I added about 1/2 gallon of water to the coolant. I got it started just by turning the key. It had very little engine power. Had to push the throttle all the way down to get onto the highway, and acceleration was very slow. When we got home, I popped the hood to take a further look. The battery was hissing and bulged. I then shut the hood, as I did not want to deal with an exploding battery, and waited a few days. When I went to restart it, the battery was fully dead. I replaced the battery, and checked the voltage. With the engine off, I am getting 11.8V to 12.5V. When I start it, I am getting 17V to 19V at the battery terminals. There are no engine codes. I assume this is partly that it has not run long enough after replacing the battery, but maybe there is no code for this either.
I had the alternator replaced a little over 2 years ago (with a 2 year parts and labor warranty that expired 5 months ago). Back then, the car had died as it was driving. Barely got it off the road, and had to have it towed to the shop. Alternator was putting out nothing then.
I am thinking it is the alternator, but want to see if there is anything else to check first. I should mention that this engine has also gone through several Coil-Over-Plugs. The alternator R&R has a 3.5 hour shop allowance, and the owner of the shop the last time said his mechanic was never going to touch an Escape alternator again (no fun, and it took him way over the 3.5 hours).

 

I suspect that the regulator has gone nuts[tech term...], and is giving full field to the alternator so it produces its full output no matter the base battery voltage. Your alternator is working fine, too fine.
I think most have a built-in regulator that can be replaced without need to replace the whole alternator. It is a 'bolt-in part', ONCE you have the alternator out.
The mechanic might not have known that you can remove the upper intake manifold and thread the alternator out between the engine and the firewall. No need to disconnect the drive axle, drop the axle center support, etc. You may have to unscrew a bolt or stud and leave it in place in the hole in the alternator, loose, while finagling it out, and be sure to put it back into place when re-installing. Do NOT leave off the air ductwork as it helps cool the alternator. Some shops have lazy mechanics that figure they know better, and "you don't need these parts...". I disagree, as FoMoCo would not add excess parts to hundres of thousands unless needed. Go figure who spent the most on engineering... or not.
Anyway, you can buy just the regulator and R&R it, or go for a complete rebuilt. Here are a few sources, (maybe):

# 28212 - Alternator Rotor 95-110 Amp/12 Volt For Ford Small Case 6G Series 95-110A Alternators. 100% New, TOP QUALITY

https://alternatorstarterrebuildkits.com/

and a rebuild 'guide':

DIY Alternator Rebuild - Mazda Forum

This is not rocket science. People seem afraid to mess with them. I don't know why.

I DO know that some rebuilt alternators fail just past the warranty. I DO know that some just clean old ones, and replace the most worn parts. Some do a good job. You have to take them apart to know. If you do replace, make sure to test on the bench at the store before doing the labor. Duds do happen, right out of the box. YMwV.
tom

 

I don't think that I've read of somebody pulling an alternator and just replacing the voltage regulator. A complete rebuild sounds better just in case something else is just about to fail as it's not a simple job to remove one.

I have read of many third party units that don't last very long too.

 

The only difference is the 'pulling' part. I have replaced regulators on vehicles without touching the alternator. The gizzards, besides the regulator, are functional, or it would not put out the voltage noted. The things that wear are the bearings, slip ring brushes and the rings them self. All else is static, non-moving.
I do not get paid for my labor time, and can take the time to do this sort of thing. I also KNOW what was done, and when, and can't blame someone else for failures.
I have gotten 'rebuilts' that were to be mounted on a 4.0 in an Aerostar. Just dandy to get at... not. Installed, with no problems, save time invested. A few days later, the owner, wife's best friend, comes over, and visits. After startup on the way home, she goes to leave and the alternator light comes on. I looked, and the pulley was flopping in the breeze. They had not tightened the large nut holding the pulley to the shaft. It was dumb luck it didn't fall off going 65 down the freeway, scrambled the belt, killed the power steering, and water pump. That's my most recent experience with a 'factory' rebuilt, and I don't want to repeat it, nor do I want to put something in that will fail. The output can be checked on a tester, the bearings inspected, the slip rings & brushes checked, and you have a pretty good idea of overall condition. Short comment is who do you trust? OTOH, get it done by a shop that gives lifetime warranty on their labor. They're out there, and you can get lifetime on the parts, too, if you shop. I just doubt it will do any good when you have moved to East Buffalo, AZ from Truebridge, VT.
It is your moolah, do what you want. I have no say, and no problem in how people do their thing. I just want them to consider 'things'. The parts in question are really simple things unless you get into armature repairs, which require special tools and equipment.
tom

 

Good points mentioned but can you purchase a voltage regulator at your corner auto parts store that does carry the alternator?

For my 2009 Escape a Motorcraft GR821, two days with Amazon Prime which many times is three days. A Ford dealer should carry that I'd guess and would be quick but maybe at a price!

 

tomw and wptski,
Thank you for the feedback. I will get the alternator replaced/fixed/etc. I've got to look into it a little further to find out what I get with the lifetime warranty on the alternator, since it was purchased originally through the repair shop.
Do you think the voltage issue is also causing the rough running and poor acceleration? Or will that be something to address once I get the alternator / voltage resolved?
Thanks,
Brian

 

Well that same voltage is supplied everyplace else too but you'd think that the PCM would have it's own voltage regulator for protection. Sensors are more like 5V so that's from the PCM.

 

Got it out, and took it into the shop that replaced it 2 years ago. They took it to Napa, who tested it and confirmed it was bad. They gave me a free replacement under the lifetime warranty. Now, since the alternator is out, I am going to pull the rear exhaust manifold. It has been leaking for about 8 years. Hopefully it is just the $13.99 gasket, not the $500 header.

 

Which removal method did you use?

 

I removed the axle half shaft and took it out that way. I thought that I might want to work on the exhaust also, and that method gives better access. Also, I have experience removing half axles from some work I did on my Chevy truck earlier in the year, so I had more confidence in that. And now that I took some cross-supports out to get to the exhaust manifold (I have the bolts soaking in PB blast right now), I figure I will also change the seal on the oil pan which is also leaking.

 

I started a complete brake line replacement job(last year, still at it) and had a fitting on a rear brake drum. PB Blast, Liquid Wrench, WD 40, etc and nothing worked. I ended up using a MAP torch.