Factor Alternator ONLY??

From an engineer's point of view... that's far-fetched. NOTHING is simpler than an integrated alternator.

The associated wiring, however, with possible bad engine and harness grounds, connection faults etc. makes it difficult to resolve that type of problem... but that is where they should look.

This is something I've never heard before, but I can see it happening. In about 2000 Ford started tieing the alternator field into the PCM to more accurately control the charging system output. I'm sure that system has become more integrated since then making the alternator much more specific to the vehicle. Once cores become more available in the Aftermarket stream, they should become more available in places beside the dealer. I remember when GM changed the design of their alternators in the early 90s(SI series?). They were said to be non-rebuildable and too expensive to produce for the aftermarket, or something along those lines. The first remans available were trouble prone and expensive. After a few years they were readily available.

Argghhh... ask them WHY that is... they'll probably tell you it's because the voltage regulation is done by the PCM.

Forgot... sorry, still that's a lousy excuse and IMO, a stupid uneccessary design.

Yeah I thought of that at the same time... check post times.

If you're using one of the chain auto parts store rebuilt alternators, reliability is a crapshoot, and you'll waste a lot of time finding one that works well for any length of time. If Ford's using a Misubishi-made alternator as OEM, those seemingly can't be rebuilt reliably, and you'd be better off just getting a new (not rebuilt) alternator from Ford or some aftermarket company like Pa Performance or WaI.

Actually, this design (or some variation of it) is quite necessary due to all of the electronics in newer vehicles. Common charging systems produce wide swings in system voltage and spikes that can damage electronic components or interfere with the communication network between these components. As the tolerance on the electronic controls gets tighter, better voltage regulation is a must. Sometimes it sucks to deal with advances in automotive technology. But,like disc brakes and electronic ignition, after we become familiar with it it won't suck as bad.

They said the reason for this is that the car was built using a "smart alternator", which contains a circuit board, and that the aftermarket alternators cannot function properly with the computer. They did say they checked the wiring harness, the grounds, all the cables and wires, etc. Of course, they are not entirely sure that this will fix my car either. They are going by what a Ford Engineer told them. Apparently, the issue my car has been having seems to have everyone stumped.

We'll see....

While I had NO problem dealing with other 'advances' in automotives.. particularly Electronic Ignition and REAL Fuel Injection, both of which encouraged me to AGAIN work on my own cars because NOW I understood the technology... I look at this as a 'step backward'.

WHY? Because the Alternator STILL must have an internal regulator OR ELSE there might be a failure resulting in blown batteries and the very circuits these advances were put in place to protect.

As the cars get older and the wiring less reliable, the incidence of coincident failure will increase.

An external regulator is still an external regulator and subject to exactly the same foo-pahs as the old mechanical version.

{And BTW, I thought you must have read me enough to not put me in that box?!!!}

Backyard Mechanic wrote:>... exactly the same foo-pahs as the old mechanical version.

Actually, I'm in "wait and see mode" on a lot of systems myself.

What box?? If maybe you thought that I was saying you are unwilling to adapt, I'm certainly not. You have my apology if it sounded that way. IIRC, you arent a tech per se (working in a shop every day), but a very competent DIYer? You like to know the how and why of things. I was just trying to explain why such a system is needed. The first time I saw that charging system design, I thought it was one of the most random, unnecessary things I'd seen. Once the reasoning behind it was explained to me, it made sense.

Regards, Tom

Where have you been buying these replacement alternators? If it places like Autozone or Pep Boys, or similiar such places then expect the "new" ones you buy there to maybe last a month if you are lucky.

I got them at VIP. First one made the car die the very next day. Second one seemed better, but problem was still there, and getting worse. Then the dealer replaced the computer, and is now saying the problem (they think) is the aftermarket alternator. If it's not, then I'm REALLY in trouble, because no one seems to be able to figure out what the problem is.

Hello ,

When I had random intermittant electrical troubles with my car , I suspected that there may be a poor connection at the point where the ground wire from the battery is bolted to the motor or the chassis . I did not disturb the original wiring . I got some new wire , crimped terminals on the ends , and connected the negative terminal of the battery to the chassis and to the motor .

This is a redundant device ; it duplicates the wiring that is already in place from the factory . It worked for me . All of the electrical devices are working properly now . This was easier than trying to reach the connection point of the factory ground wire which was difficult to access .

Many cars have problems with ground connections . Often the problem is thought to be some other item. I have seen needless replacement of battery, starter, alternator, or other items because the real source of the problem was not determined . Look at the ground connections first . Installing a second ground wire as described above will not hurt anything .

Well, i been stewing on this a couple hours... and I still cant see the justification.

I can understand a sense/shutdown circuit tied to the alternator's internal regulator, THAT makes sense....but full remote regulation flies in the face of known best practices. It's not used in Personal Computers, AFAIK.. the PS supplies a clean voltage and the CPU chip further regulates according to heat, IIRC.

Given the far harsher automotive environment and probabilty of ground- loop faults at some time (and I've troubleshot a fair number of those in much cleaner systems), it just doesnt make sense.

OTOH, maybe that "sense/shutdown circuit" is what we're actually talking about, here.

I had a similar problem with a GM product. Local GM could not find it. Finally went to a local auto electric shop. They found it quick. A wire in the dash which vibrated against a sharp dash brace edge causing an intermittent short.

Ok, picked up the car last night. Turns out they were right! (go figure). The new alternator actually fixed the problem! I turned my headlights on and it was like the sun came out! (they've been very dim during the whole ordeal, even when they weren't flickering). Now I'm working on getting my money back for the aftermarket alternator that was put in by VIP.