WTf?

Possible bad ground I reckon. Check the ground from the battery to the engine cradle.

 

Tach problem? Sender? The car itself goes up in the Rs ok? No hesitation?

 

Relax, it's not that. Probably he sender. Or a bad connection or ground.

 

Check the condition of the battery.

 

My money is on your “new” alternator not charging the system.

One of the basic charging system diagnoses is a fluctuating / bouncing tach at higher revs. The reason is that as the revs go up a greater demand is placed on the battery so the voltage drops and the tach is the more sensitive to voltage drops than the ignition system.

 

For what it’s worth, I’ve seen this many times in the past, it’s always been the alternator.

Until you diagnose the problem properly I wouldn’t trust it to drive, at least not without your AAA card. If it’s really the alternator the battery will eventually give out and leave you stranded.

 

Is the new alternator properly grounded, with a ground strap from the alternator to the oil sump?

 

Ah yes.......the old "alternator bad-from-the-box trick" again. Maybe this is your problem as well but I would check the ground strap from the alternator first. The stealerships and their supposedly "factory trained" grease monkeys often forget to put it back on. Ever wonder what they do with those pieces they find remaining after you have driven away in your car? "Re-sale, re-sale!" On the other hand, I just went through a "bad-out-of-the-box" episode with one of those wonderful gold-plated-stick-it-to-you Ferrari masterpiece alternators. Put the thing on the car and it put out a whopping, almost constant 12.7 volts. Not so bad for a generator off of a 1952 International tractor!!!!

Threw it (literally) back into the lovely Ferrari show piece box and took it to the local alternator repair shop and when we bench tested it we found TONS wrong with it. Both the rectifier AND voltage regulator were screwed. Not to the point of not functioning but to the point where you could never run it and hope to go to 7-11 three blocks down the freaking street. Pathetic to say the least.

AND THIS IS WHAT WE PAY FOR?!?!?!?!

Living in the Middle East has its disadvantages when you have to return something back to the Mothership. It is infuriating, the number of parts that are questionable at best from Ferrari. However, living in the Middle East does have one advantage in that necessity is truly the mother of invention and with the help of Google invention turns out to be a more reliable Ferrari with better parts at 1/5 the price! Even things like fuel and oil filters. Wanna know who makes those and where to buy them??????? Google baby, Google.

I'm tired of lining the pockets of Italian shareholders who, if they didn't dominate F1, wouldn't even HAVE an automobile that is marketable let alone reliable. KIA is more reliable. Maybe even Skoda. Don't get me started on the "oh but Ferrari is much more complex automobile." This is a cover up, catch-all, Maranello Manure statement from those that have never taken one apart! And for all of us that have taken them apart, I guess we scratch our heads, have another sip of beer and say "Good thing it looks good!"

 

Hi Albert,

Sorry to hear about your electrical gremlins. But believe it or not, the clouds have parted - and they reveal this silver lining - http://emelbon.tripod.com/eugeniosferrariservice.html

Eugenio is a Ferrari angel. He will prevail. He will find the gremlin and remove it from your car. Your zip code makes this very doable - your time frame may be an issue though honestly, don't let it be one. Call E and talk.

Dat's all I can say - -

Cheers, Hank

 

Another solution found for some of these gremilins is to check that the "S" wire which connects on the positive terminal (clamp) at the battery. Apprently this red wire (14 gauge or so) is molded into the lead clamp itself, and can fray or break off from the clamp causing problems. Worth checking. Also clean and check all the connections at the terminal block under the right side engine cover plate (passenger side).

These tips may help also:
http://www.ferrarichat.com/forum/showpost.php?p=137803385&postcount=3

 

Ah yes!!!!!!!!!!!!!!! Good catch on the battery wire issue. I drove myself nuts for an entire weekend and then noticed that discreetly the wire had corroded and parted ways with its little lead buddy. A divorce of sorts brought on by time.........just like all the rest I reckon. Check that puppy! Reattach and run! simple.

 

Bad part or they connected two wires backwards causing a load. If they replace the alternator the problem persists look for operator error on wires.