1994 Spider Foot Well Fuses

Where did you get the values from, Anthony? F348 Spider Owner's Manual? Generic pdf Workshop Manual? Do they agree?

I believe there were one or two factory-recommended upgrades on the F355, but there seems to be quite a few differences on your F348 photo. The later models may have had some differences due to engine management changes and the spider may have had an increase in fuse power due to the addition of the Window Control Unit (?). Did the spider have a mousetrack seatbelt? I don't think there would be any changes for this, however. Most of the mousetrack seatbelt stuff ran directly off the battery.

 

To me, it sounds like a bit of "creativity" on the part of the previous owner, but I defer to the 348 experts.

The generic workshop manual (which includes 2.7 engine management, but has no spider/no mouse seatbelt details) agrees with your Owner's Manual. Oddly, I have a decal on my relay panel cover which includes fuse amperage, but in one case lists an equipment item which is not even applicable to one of the fuses, so it's hard to know how accurate some references are.

 

Some of the decal values make sense:

A spider doesn't have rear window demisting, so a smaller fuse is ok (for heated mirrors)
US cars have combined front fog/daylight flashers, so it makes sense to go to a larger fuse (than the generic workshop manual)

Was there a larger RH radiator fan on later cars?

Oddly, the parts manual only lists variations for RHD/LHD and 2.5/5.7

 

Don't assume that all that is written on the decal is all that is powered.

For example:
Fuse 1 (cigar lighter) also powers the courtesy light time delay module. Even so, 25 seems high. I wonder if the previous owner was running some high powered accessories from the cigar lighter.
Fuse 3 (daytime flasher/fog) also powers interior lights and glovebox power outlet.

15 is the smaller oil radiator fan. 13 & 17 are the water radiator fans.

 

RH water rad fan (Fuse 17) is also smaller, same size as the oil cooler fan, so there is logic that both, the oil and RH water, fans have the same 20A fuse specified. The Workshop Manual and all Owner's Manuals, 1989 to 1993 (EU, USA & GTB, GTS) that I have all show 20A fuse for #17, RH water rad fan. However, the sticker on the fuse box cover of my 1991 348 shows 25A fuse for #17. I prefer to follow the sticker as these are specific to the model/year and the manuals do have some typing errors.

The fuses are also sized to the size of the wiring to a consumer so that, in the case of overcurrent drawn by the consumer, the fuse blows before the wire gets very hot and causes fire. I believe the wires to the LH and RH water rad fans are the same size so, having a 25A fuse for the smaller RH fan should be fine.

 

I was looking at the water radiator fan motors in the parts manual on the later model cars and noticed that they had the same P/N motor. Are the water radiator fans different sizes? (these have a different part number)

https://www.ricambiamerica.com/car-diagrams/ferrari/v6-v8/348-group/348/cooling-system-radiators.html

 

The US passenger side had 9 in radiator and the drivers side has 12in fan always the same one. The 12 in one draws 30 amps on start up the 9in draws 17 amps on start up if I recall. This is why I added PWM to both fans thanks to Miroljub. If those fans go on and off frequently like in the SW there is heat build up. There are posts of fuse boxes meting at the fan fuse locations. Again PWM completely solves that every new car has them for a reason.

There are 2 sizes. They are old and draw more power due to age, good idea to replace them if nothing else.
Spal 30102061 Puller Fan - 9In
Spal 30102038 Puller Fan - 12In