HELP...Battery, voltage regulator or alternator? You make the call.

If I had to guess I would say the battery is at fault. If the alternater was bad the car would have died during your drive I would think.

Do you have a volt meter? What does it read while the car is running?

 

Oh, and the voltage regulater is built into the alternater.

 

Get to the battery, remove the cables, clean the terminals and the cable ends really good. Connect them back, try again and see if the problem goes away. If not, at least have your battery checked out by pepboys or something like that.

 

+1 Sounds like a bad connection somewhere. Battery? Starter?

 

buy a multimeter at harbor freight for $7, hook it up to any old cigarette lighter adapter from some broken POS in your garage, plug it into the cig lighter and read voltage. ~14 volts or greater and the alternator is fine meaning the battery isn't holding a charge. less than ~12 and your alternator is the issue.

best part is you end up with a multimeter for $7.

 

The fact that the starter is turning the motor, but the car is still not starting makes me think it's not a battery problem or an alternator problem, but something else entirely. That is, unless the starter is turning very slowly during the times when it's failing to start.

An easy test to see if your charging system is working, is to charge your battery completely, then remove the charger, start the car and measure the voltage across the battery (battery is hard to get to, but there are other places where you can measure the voltage while running, like the lighter socket, and I believe there is also power access under the engine lid on the right hand side). While the car is running, you should see 14 to 14.5 volts. If it's less than 13 volts while running, then I would agree that you have a charging problem.

To test the battery, you'd need to load test it, which any car parts shop can do for you, but would require removing the battery. It's unlikely that such a new battery would fail.

Good luck. Let us know how it goes.

(oops! I see Lane beat me to it. ok, i'm redundant)

 

I went through similar battery issues as you did last month.
Battery was less than 6 months old but the 355 was hardly driven through the rough winter that hit France this year.
As you did,I hooked up the charger a couple times for full cycle charge.
At first,the car would start a couple times but with weakness and hesitation.
When weather got better, before enjoying a nice drive, I took her to car wash.
After she was all clean and shiny,car wash guys couldn't get her to start.
Luckily,they're located right next to high end sportscar dealer who kindly removed right engine bay panel to access emergency battery connexions in order to jump start the car.
I was explained that even though battery was fairly new and fully recharged a couple of times with charger, not driving the car for a long period of time would ruin it and therefore make it unable to hold the charge.
I put a brand new battery in and everything was back to normal.
Also,when I don't use the car now, I turn off the kill battery switch located in the front trunk.
Everything works perfectly fine now and car always starts effortlessly.
The important thing to do when you use the kill battery switch is to make sure when you turn it back on and start the car, to let it idle for 10minutes with all electrics like A/C,radio wipers off in order to reset all car parameters to factory settings.
Then you're all good to go and hopefully you'll never encounter such issues again.
Hope this helps,
cheers from Paris,

olivier

 

Most likely, it would be highly cost effective to have the existing alternator/regulator rebuilt versus buying a new or remanufactured one. The key is to find a top quality local rebuilder - your mechanic will hopefully know of one?

One other point I haven't seen mentioned. Alternators often have a "partial failure" mode where they produce low voltage at idle speeds, then produce increased (normal level) voltage at higher speeds. It seems that your problems first began after the car idled for a while with a high electrical load...i.e. the battery may have been effectively discharging even though the alternator was putting out SOME (but not normal level) voltage. The point is that you need to check the voltage at various engine speeds and see if the alternator is "keeping up" at idle speed under load (headlights on, blower motor on, etc.).

Also, if the alternator does appear to be performing properly at all speeds, the advice given above about thoroughly cleaning cable connections and tightening them at both ends is spot on, as is the suggestion to have the battery load tested, even though it is relatively new. A partially charged battery may spin the starter, but not have enough voltage to allow the ECM and fuel injection systems to operate properly, hence the no start problem that is remedied by providing an external power source. Batteries don't take kindly to abuse, and yours may have been damaged by the multiple discharge/fast recharge cycles it has been subjected to.

Good luck - hope this helps.

Bob

 

replacement Ferrari alternator 1500 - 2000
Total rebuild at any local alternator shop (partial DIY) 250 max
get it working rebuild (DIY) 100 max

the math is up to you.