1996 355 Spider. Alternator light sometimes flashes randomly. Sometimes it stays on constantly for quite a long time ( 15 - 20 minutes) before starting to flash randomly again. Alternator has been rebuilt by Ferrari authorised 'outsource', and been back to the main dealer 3 times for same problem. Original problem diagnosed as a faulty alternator ... it was then rebuilt. However it was 'rebuilt' in the wrong way. Apparently 2 types of alternator .. one for carburator cars and 1 for injection.... I got the carburator version ... same shape ... less pins .... >>> problem not solved. Eventually after the wrong rebuild was discovered, it was corrected and was OK for ~ 2 months. Now back to flashing etc.... I should say that the battery never runs down .... even when running with high load on battery. Is there anything else that controls the alternator light on the dash?
The problem with rebuilding the alternator is the shop that did it used the wrong regulator. They need to use the best heavy duty regulator that they can. If they don't then that is why you will get the light coming on. The alternator will still charge the battery and power the car, but it will shut the current off to the battery premateurly so it won't get over charged. That is when you will see the light. So have them put on the propper regulator and it should solve the problem. Or you can do it yourself. I'm not sure what alternator the 355's use but I have a Nippodenso on my 348. I have taken it apart and put it back together. They aren't hard to do. They are held in by two bolts. You can remove it from the bottom of the car. But since it has only been a few months take it back and have them put in the correct regulator in your alternator. Let us know how it goes.
Yeh .. really. One of the problems was that the expert in the 'outsource' shop was not there to do the work .. so it got passed to someone else and told .... Ferrari alternator .... fix it.
Note there was an update to the alternator grounding on early 355's. I'm not sure if 96 year was affected or not...but they added an extra ground strap to the car chassis. Check with the dealer on where the VIN cut-off was. It is about a $20 part...big wire with terminations on each end. This could be part of your problem.
Changing the oil the other day i did notice an earth strap from the alternator body to the chassis ... braided wire about 3/6" thick and ~ 6" long. Regards, Pete