355 electrical system/engine shutdown

hard to tell, did you check all the alternator and battery connections?

 

You left your baby on the side of the road overnight? Shame on you!

 

Check your grounds. Check the crappy positive side in line connecotors/switches comming off the battery

 

The thermocouple electronics(monitors overtemp condition in exhaust) can cause the problem. But, I have never seen a case in which both of them failed, or sensed an overtemp condition at the exact same time. Check all the connectors, clean them, ect., for the thermocouple electronics, located in the engine bay. It is also possible that the fuel pump relay is acting up, and I believe there is also a main relay that can cause the problem. These relays should be located in the passenger side footwell.

Did you try to crank the car after it died ?? IF so, would the engine turn over, but no "fire in the hole" ?? This would provide more clues as to what the actual issue really is.

Ha, where is a freaken' cop when you need one ?? LOL.

 

Not surprised that FoA had no idea about your problem. It sounds like a F__cked up relay, which overheated, and once cooled down, it started to function again. Perhaps you could try to repeat the problem by simply starting the car and let it run in the garage for awhile and see if the problem returns. While it is running in the garage, perhaps you could also lightly tap on the relays and see if they crap-out. IF the problem occurred once, it will most likely happen again. I had a similar problem with the 512TR, in that on occasion(randomly) it would not kick-in the starter solenoid, and FoA just wanted to replace the starter motor, which of course didn't help the problem a single bit. I finally got sick of the problem, and tracked it down myself, armed with only a VOM meter. It turned out to be the high-beam headlight relay, which was factory wired to the main key services relay for the purpose of killing the hi-beams when starting the car. The hi-beam relay went "south" internally, which in turn drew the current/voltage, instead of going to the starter solenoid wire. A $12 relay, plus contact cleaning fixed the problem.

 

WOW, 512PROF. that must have been a real adventure to find!!!! i am guessing one would start with the " key wire " that energizes the starter and see what is in the pathway on either side on the ignition circuit??? current loves the " least path of resistance" so a bad relay will usually suck up amps and get really hot before you know its good and toast!!! i detest electrical gremlins, especially when a proper wiring diagram is no where to be found!!! a belated great job to you, hope our thread starters problem is something simple!!!! michael

 

For sure, Ferrari electrics, or most cars for that matter, tend to be "mysterious" and somewhat convoluted, but they are all basically rather simple, becasue its just a DC voltage system that follows the simple Ohm's Law in most cases. Fortunately, I have a personal advantage because of my degrees/background in electrical engineering.

The owner's manual has a nice section on the fuses and relays which documents all the relays and their placement, so while tracing the wire for the starter solenoid, it was found to also have a connection to the hi-beam relay on the relay/fuse circuit board itself, and the VOM meter indicated a hi-impedance short to ground within the hi-beam realy, and since this was connected to the starter wire - BINGO. Relays can fail in different modes, which always adds to the trouble shooting mess, but after removing the hi-beam relay, all measurements were normal, and then I decided to open up the relay to confirm. Yup, there was corrosion inside which bridged the internal coil to the relay case. As a follow-up, one of the mechanics at FoA(a real nice guy) let me borrow the shop manual to confirm my findings, and sure enough, that was how Ferrari designed it.