Ferrari F355 Radiator Fan - Running HOT!!

Always start with the easy stuff! So first, go to the passenger foot well, and peel back the rubber foot cover. You will see two large screws, they are the aircraft type that require a half or so turn to "unlock". Then it will pivot at the bottom and fall backwards toward you. Find the 30 amp fuse for the left radiator fan, and you can either put test leads on the two exposed metal points with a continuity tester, or remove the fuse and exam it visually. Hopefully you may just need a fuse (check the right one too, while you are at it). It is not uncommon for the fuse to occaisionally blow, from high resistance. One common cause for this is while driving in the rain, according to Dave Helms (a ferrari technician) the resistance of the rain going through the fan blades can cause the motor to strain, and subsquently cause a blown fuse. The other reason for the fuse to blow is your motor is on the way out.

If the fuse is good, the next logical possibility is the radiator temp sensor. The left (driver's side) fan is triggered by a temperatur sensor screwed into the left radiator. I have not done this, but it can apparently be accessed by removal of the left rear fender liner. This will require jacking the car, and removing the left rear wheel, then a bunch of fasterners to remove the fender liner. Once removed, you can access the temp sensor. I think it is on the top right side of the radiator. Remove the plug or two wires attached to it. Turn the ignition switch to "on" and short the wires, which should cause the fan to operate. If it does, then you just need a new temp sensor. If not, then you need to check the fan motor itself. And see, if while the temp sensor is shorted, that the motor is receiving 12 volts. Good luck!

 

It could be...but it could also be the motor...so you have to perform the "steps".... good luck and report back.

In order of most common solution to this problem on a 355:

1) Fuse
2) Thermo switch
3) Fan motor or relay

 

Well technically what 355 Spider said is what you should do...but plan 'B' is to just drive faster I'm always well under 190F at 80+ mph

 

Found the connection plug for the fan itself a problem on 2 cars this summer.

Dave

 

Very common solution, if you've already diagnosed the other stuff.

Jack up the left rear, remove LR wheel. From here, you can access the fan (pulls air through the radiator). You can now unbolt the entire fan assembly. I replaced the unit on mine, because where the fan blade is connected at the center to the shaft, the shaft from the motor itself uses a tiny metal pin to make sure the fan blade spins along with the shaft when the shaft rotates. Very common to have the plastic in the fan blade (molded) to wear and then break, so that the motor shaft will spin, but the blade won't. Theoretically, you could thus just replace the fan blade, but Ferrari does not sell the blade by itself.

If you replace the entire assembly, just be aware the assembly has been updated (so that the mounting points have an additional spacer molded in, IIRC.

Let us know.

vty,

--Dennis

 

If you have to replace the fan, it is an easy repair. Contact Daniel at Ricambi, he will get one right out to you. I got one last year, took 20 minutes to replace, works like a champ. This year the fuse went out, even easier fix and only $2.! Good luck.

 

I had the LH fuse blow about 1.5 years ago and has not recurred. JSL, did the fuse blow on the newer fan? I am curious what causes this, as I have heard of others having them blow regularly (every few months). Dave Helms has determined it can occur from the fans activating while driving in the rain, and the rain can cause added resistance. Any other reasons? Does age and wear contribute? It seems that it must just be a voltage spike/surge as the fan comes on that causes this. Simple cure might be to install a slo-blo fuse in place of the fast acting one...but they are not easy to find. I have also heard of using a simple 10 amp plug in circuit breaker in place of the standard blade fuse....those are easy to find...I have seen them at most auto parts stores for $5.

 

You know, that is a good question. Both fuses blew at the same time. I only replaced one fan last year. It was a hot day, a friend was driving the Ferrari following me to a show in my other car, the A/C was on and the fuses blew. May have all contributed to it. No problems since.

 

I meant to say "30 amp, plug in "blade type" circuit breaker"...not 10 amp.

 

I have a 355 with the same problem. I was wondering what was found with this issue. Thanks.

 

The fans as they age start drawing excessive current, causing the 30 amp fuses to blow. Also, the fan can seperate from the shaft. Easiest fix is to replace them. An inexpensive source was found in another thread and posted here for your convenience: http://www.thestreetrodcatalog.com/cgi-bin/store/cp-app.cgi?&pg=store&sub_pg=prod&ref=783

You will need to cut the plug off your oem fan motor and splice it onto the new one as they are different. That is the only difference. Swapping is not a big deal. Jack up car, remove wheel, and fender liner. Fan is simply bolted in, remove and replace.

 

My drivers side fan quit 2 days ago. It was just the 30AMP fuse. A quick fix. Had alternator problems recently. Was wondering if it might be related. Prob so!