Megafuse

The WSM only has these photos:

Image Unavailable, Please Login

Any clues? The cover looks asymmetric (front to rear).

 

The megafuse goes directly to the battery bus bar behind the left hand seat. If you can't get the mega-fuse cover off, you could remove the panel behind the driver and check the volts on the battery bus bar.

Image Unavailable, Please Login

Look for the big red wires.

 

Do you have instrument power in general?

The instruments (including the lighting) are powered by fuses in the forward luggage compartment (AF9 & AF15). These fuses get power from the battery (via maxi fuse 5) and the ignition switch respectively. Also, for dash night lighting specifically, an earth is required from the steering column light switch. Once the instrument cluster receives an earth, the general power going to the instrument cluster powers the night lighting. When you turn on the lights, do you get the sidelights on symbol on your dash?

Image Unavailable, Please Login

The mega fuse is not really involved unless you're talking about some serious power issues (e.g. fuse AF15 is powered by the ignition switch which is powered by fuses behind the seats (which are powered by the mega fuse). Does anything happen when you turn the ignition key on? If not, check fuse PDF18 behind the right hand seat or maxi fuse PSF19 behind the left hand seat for live battery power.

The no start problem could be anything at this point. Let's see if we can sort out your lighting problem first. It may or may not be related.

 

Correction. AF9 gets power from maxi fuse 4. There is a confusing numbering system on the contacts in the wiring diagram.

This wiring diagram may help with diagnosis of the lighting problem:

https://www.dropbox.com/t/u4uAQixCom4ZsKjX

It's a work-in-progress.

Link expires in 6 days.

The maxi fuse is in the middle on the right. The instrument panel is identified as E003. Let me know if you need connector locations.

 

No, I mean the larger fuses next the battery and also behind the left hand seat.

Image Unavailable, Please Login
Image Unavailable, Please Login
It's strange. The symptoms seems to be pointing to a flat battery, but you've said the battery is showing 12 volts. By the way, do you have a trickle charger (tender) and have you removed it? On some cars, the official Ferrari battery charger inhibits starting when plugged in (to prevent you driving away with the charger plugged in).

You may have a power supply problem in your instrument panel. It's a known problem.

https://www.ferrarichat.com/forum/threads/wiring-diagram-instrument-panel-360.357681/#post-141247103

 

This probably means live battery power is reaching the doors. Your glovebox light, parking light switch and interior light is probably working, too.

I would check for voltage on fuse AF15 in the luggage compartment with the ignition turned on. If not, work backwards towards the source:

i.e. Check for live battery voltage on fuse PDF18. If no luck, check for live battery voltage at maxi fuse PSF29.

I assume you have an Owners Handbook for your car.