The fan doesn’t run. Or the fan never stops.
The coolant temperature rises. Or it doesn’t rise at all.
Are you having any of these problems?
The fan switch isn’t necessarily the cause, but when it is suspect, simply replacing it with a new one is sometimes better than testing the old part, both in terms of the risk of later failure and the cost in time.
Views differ on preventive maintenance and replacing parts together, but fitting a new one while you are already doing work such as a coolant change may give you peace of mind.
Radiator fan switches (temperature sensors) are available in our online shop. You can order and check stock from the links below.
👉 For 348 / F355 (92°C – 87°C type)
👉 For 348 / F355 (87°C – 82°C type)
👉 For 360 / F430
What is a radiator fan switch?
Function
The radiator fan switch turns the fan ON when the coolant rises to a set temperature, and OFF once the coolant has cooled down to a certain point. It is the ON/OFF switch for the fan.
Internally it is a coolant temperature sensor. It detects changes in coolant temperature and repeatedly makes and breaks the circuit to control fan operation.
Mounting position
The mounting position differs by model, so here we explain the 348 / F355 and the 360 / F430.
348 / F355
On both the 348 and the F355, the fan switch is fitted to the radiator.
The position is on the right on the 348 and on the left on the F355, reversed for some reason. (Why, we don’t know…)
On both cars it is fitted to only one of the radiators, and a single sensor controls the fans on both sides.
360 / F430
The mounting position of the fan switch also differs between the 360 and the F430.
On the 360 it is fitted directly to the radiator, while on the F430 it is fitted to the cooling line.
Operating temperatures and switch types
For 348 / F355
This is a simple single-circuit design, switching only between ON and OFF.
You will see figures such as 87°C – 82°C. These mean:
ON at 87°C (the fan starts running)
OFF at 82°C (the coolant has come down to the proper temperature and the fan stops)
For 360 / F430
This one is a two-circuit switch.
It is marked “92°C – 87°C / 97°C – 92°C”.
ON at 97°C (the fan runs at high speed)
ON at 92°C (the fan runs at low speed)
OFF at 87°C (the coolant has come down to the proper temperature and the fan stops)
What happens when it fails
The fan doesn’t run, or it never stops
Age-related deterioration or an electrical fault has left the switch unable to change over correctly.
The fan runs only when the air conditioning is on
Fan operation has two control circuits: one based on coolant temperature, and one for cooling the air conditioning condenser. In other words, this symptom occurs when the fan is running on the air conditioning signal, but the signal for engine cooling is not being produced correctly. The fan motor itself is alive, so the switch is what to suspect.
The temperature rises only in traffic
While driving there is enough airflow to cool the car, but when stopped or moving slowly the fan doesn’t run and cooling can’t keep up. This is one of the most common patterns of fan switch trouble.
Points to note when diagnosing from the symptoms
Cooling systems are controlled in a fairly complex way.
・Coolant circulation by the water pump
・Temperature management by the thermostat
・Cooling by the electric fans
・Control by the ECU
Because these all interact, the difficulty is that symptoms such as “the temperature rises” or “the fan doesn’t run” cannot simply be pinned on a faulty fan switch.
When the symptom comes and goes, pinpointing the faulty part takes a great deal of time. Taking work efficiency into account as well, replacing a suspect part with a new one is faster.
This is my personal opinion, but when it comes to fan switches:
if in doubt, replace it!
That is what I would say.
Online shop
The parts introduced here are available in our online shop.
You can order, check stock and see full details from the links.
[Compatible models]
Ferrari radiator fan switch, part number 158655 / 140314
・348
・F355
・456M
・512TR / 512M
・Mondial 3.4T
Ferrari radiator fan switch, part number 176322
・360 Modena
・360 Challenge
・360 Challenge Stradale
・F430
・430 Scuderia
・430 Challenge
Contact Us
Contact Form
Email: importparts@italycar.jp
Contact: Mitsunori Ninomiya
Diapalace Momoyama 302
3-1619-2 Momoyama, Midori-ku
Nagoya City, Aichi
Zip code: 458-0002
Japan