the radiator fans will not turn on Ferrari 360

Correct. If you have power at the fuses and have jumped the relay and the fan works, then it’s a relay control issue, not a power issue.

I’m trying to understand this earlier comment. Were you saying that you thought it should work with the key off? Was there originally a problem with the frunk opening system? Was it resolved? Or, like me, you were confused about how it should work? (i.e. key power is required). I’ve been looking for a common link between the frunk opening system and the fan. The only common link is relay power. If the frunk lid is now operating as it should, we can get back to the fan control issue.

Like all standard relays, you need power across the relay coil (pins 1 and 2) and, usually, power across the main contacts of the relay (3 and 5). Did you check power going to the relay socket on pin 1? Key power is required for pin 1.
Relay socket shown below:

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Other than power, as you say, you need an input on pin 2 (an earth) from the temperature switch. You'll need access to the switch on the RH radiator to do this.

You can either check the resistance of the wiring between relay pin 2 and the temperature switch or just short pin C on the temperature switch plug to earth (with the ignition on) to see if the LH fan runs.

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The wiring goes via splice S108A, plug 32A/35A (pin 1) and splice SG3A.

Hopefully, the diode 1D1 is shown in the correct orientation, is operating properly and is not affecting the signals going to the relay. The OEM wiring diagrams don't show the orientation of the diode, so I took an educated guess.
Hopefully, it's not too difficult to difficult to identify the sockets on the temperature switch (just look for the light blue wire without the black stripe).

 

I'm getting de ja vu here. Haven't we already been through this?

The wires appear green on your car, rather than light blue.

 

I think , and I am 100% sure, for a coupe, it should work if the key is off. I am NOT confused about how it should work because I've been poking around with this issue long time ago and tested a lot of 360s.

The "frunk-can't-open-with-key-off" was a problem BEFORE I had this overheating (LH fan inop) issue. It wasn't a huge issue so I ignored it , hence it was never resolved.

so basically, I've had an old/minor issue and a recent/serious issue that seems to be related.

 

Here's what I didn't understand on your diagram. Your diagrams shows 5 prongs while the actual relay only has 4. I only see prong 1,2,3,5 as shown in my previous post's photograph.

Now, how to check 12v for pin 1?
Is this the correct procedure?

" warm up the car to 100 degrees C and
key ACC On, and
put one probe of the multimeter on pin 1 and another probe on a chassis ground?
"

 

That is a test from the thermal switch side, not the frunk relay side.

 

Yep, so , it seems that I've already completed the logical "next step"

Now, with logic deduction, I can only deduce that:

The new thermal switch is faulty, because it won't short its terminal B to ground. If it ground terminal B , the LH fan should run, as tested before.

Don't you think?

 

Are you open to the possibility that it may vary from car to car?

e.g.

The relay sockets have 5 holes. They can be used for 4 pin relays or 5 pin relays. For interest, you can even see on your relay case, that there is a metal contact between the pins. If you were to use a multimeter on that metal contact, it would act as a pin 4 (i.e. normally closed circuit between pin 4 and pin 3 except when the relay has been energised). You could say it's traditional to show the 4th contact. You may even see a 4 printed on the bottom of the relay

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You don't need to warm up the car. 12 volts should be present with just the key turned on. Yes, one probe on pin 1, one probe on chassis ground.

 

I think you mean terminal C (That's the lower temperature part of the switch). Anyway, your deduction is correct.

Either your new switch is broken or you have some kind of water flow problem and the heat is not getting to the switch.

 

No, because I've seen at least 6x 360 coupes and 5x 430 coupes that can open the frunk without ACC ON.

 

If there's a phyiscal water flowing problem, why does the RH fan turn at around 90-100 C?

Do you think I can test the switch by removing its plug and test the terminal's continuity? If the coolant is hot enough, AB and AC should have 0 resistance, I'd think?

 

Ah, yes, I forgot that your RH fan comes on at higher temperatures.

Can you stick your switch into a pan of boiling water to check the resistance between contacts C and A (I mean the metal sensing part, not the whole switch). Perhaps you have something to measure the water temperature?

 

Isn't sticking the switch to boiling water the same as warming up the car to 100 degree C?
(then pull the plug, measure the resistance)

 

I guess there are pros and cons...
You don't know for sure what temperature the trigger points of the switches are when they are on the car (the temperature gauge in the cabin may not be the same as what you're getting at the temperature switch). You might need to show some empirical data to the seller of the sensor to get a refund. If there is a bad batch of sensors, you would have to make sure a new one is working before you install it.
I guess your method is simpler (as long as you don't burn yourself in the process or get your fingers caught in the fan).

How much fluid do you lose when you change the sensor?

 

Well, I think I just confirmed one thing. It is not an electrical issue, it IS a water flow issue.
Here's what I just did 10 min ago.
I removed the RH wheel and wheel arches to expose the radiator.
warm up the car to 100 C, in the mean time, use my hand to touch the radiator to determine rough temperature figures. At about 90+(read by OBD) , I see the LH fan turns for a brief few seconds and then stopped. When it stoped, I felt immediately that the top of the RH radiator is a LOT cooler than the bottom of the RH radiator. Estimated something like 65 degrees vs 99 degrees TOP vs Bottom.
Meanwhile, the OBD still reads 105C and it continues to overheat if I don't shut down the engine.

EDIT: the reason why I didn't see LH motor run before is probably because it ran for too brief of a time to be noticed. All I observed before is a lowering of temperature at the TOP of the RH radiator.

.

 

lost maybe 1-2 liters if I remove the thermal switch

 

My hunch is telling me that, the water didn't flow well, that's why I felt lukewarm coolant at the top of the radiator. These lukewarm coolant was cooled by the fan and was kinda trapped there.

This whole thing may be because of a stuck clsed or semi-stuck closed thermostat.

 

Sounds plausible. I suppose it could be a semi-blocked radiator, a faulty thermostat or even a faulty pump.

I'm glad you noted the temperature varations. If not for this, I would have suspected the fan or some other component not being able handle the current flow... or perhaps the hysteresis of the switch (it should close at 92C, but not open until the fan has cooled to 87C). i.e. even minor cooling of the radiator caused the switch to open too fast.

 

It should't be a blocked radiator coz I removed it and put compressed water into the inlet and the water comes out of the outlet rather smoothly.
Now, I am going to replace the thermostat first. wait for my update.

 

Some background on frunk lid actuator operation:

All the 360 wiring diagrams I have (early coupe and 2003 spider) show the signal from the frunk pushbutton going through the instrument panel. The only purpose I see for this is to add a speed inhibit function (I've read that the lid shouldn't open above 5kph as a safety feature, but I don't know if anyone has tested this). Vehicle speed data comes from the ABS/ASR ECU (to the instrument panel) via a CAN Bus. Of course, this stuff needs to be powered by the key.

The only way I see the actuator working without ignition key power is if the earth signal from the pushbutton bypassed the instrument panel (via a wiring jumper).... or if the default state of the logic in the instrument panel electronics (in the absence of key power) allows this earth to pass through instrument panel unimpeded.

All the power going to the pins on the relay is live battery power, so that is not stopping the actuator working. It's only the instrument panel interfering with the earth going to the coil of the relay.

If you were willing to drive your car at, say 6kph and push the button, it would be interesting to see what happened. I don't think the airflow would be strong enough to lift the frunk (and there is a safety catch anyway).

 

I can do that.
Heck, I can jump off the car at 20mph if required , provided that there's at least 300 meter clear ahead.

 

Hoopla , Kavionni, problem solved, it is the thermostat.
everything's good now.
In hindsight, I should have known this because a year ago, the coolant temp comes down to 60 degrees C on freeway, which cause me to think that the thermostat was stuck open. But I didn't really had the time to deal with it and I just ignored it. Now, you know, its like stuck half closed, hence the uneven temp at top and bottom of the RH radiator because the cooled water in the RH radiator didn't have enough momentum to get back to circulation.

Also, I've observed that, on this particular 360, the RH fan comes on first, then at a higher temp, the LH fan turns on.

Moral of story, when you get overheating, first you need to see if both fan runs at 105 degree C.

If only one or none of the fans works----> jump the thermal switch and see if both fan works. If both fan works, then it is either your swtich is bad or somehow the hot coolant didn't reach said swtich.
If both fan work, see if both radiator is hot to touch ---- > if not , then you also get a water flow problem, probablay an air bubble, probaably a blockage to the radiator, probably a bad thermostat.

If both fan work, and both radiator is hot, then , you got a wrong reading at your dash, i.e. your car is NOT overheating ====> IT SHOULD COOL THE CAR NORMALLY UNLESS YOU GOT A BLOCKAGE IN YOUR RADIATOR OR HOSES, WHICH IS NOT VERY POSSIBLE.

 

I been following this. I just ordered a bunch of parts and the thermostat was one of them. I'm glad you got it fixed

 

Well, that was fun Four pages of confusion.



Anyway, good to see you’re up and running. Meanwhile, back to your aircon problem and frunk query

 

I’m starting to wonder if the wiring diagrams are wrong. e.g. the temperature switches are mislabelled, but I just can’t make the circuit work properly in conjunction with the aircon gas pressure switches if this is the case.

 

how is the temp switch mislabeled?