Testarossa (87) cooling fan issues

#1 reason for a fan failure is a bad, burned connection at the output connection of the fuse panel. Very common. Its advisable to install off board relays for both fuel pumps and both radiator fans.

No need for fans continuing to run after the engine is shut off. The heat of the engine will go down on its own and a fan is no longer required.

I do not recall the operating temp of the oil fans but its uncommon for them to run except on hot days. They were considered rather superfluous anyway. On 512 TR for most markets there was no oil cooler fan. With the size of the cooler it would be pretty surprising if the oil ever got to any dangerous temperature unless it was being caused by a bearing failure in which case a cooler with or without fan will solve nothing. The biggest oil temp issue is not getting hot enough.

 

I have the SRI fuse box with the high load currents off the main panel. I highly suggest any new testarossa owner to consider this improvement. I’ve never had a fuse box issue in ten years and 26,000 miles.

where are you located?

 

hello alex
would be great if you could introduce yourself a little that we know on which technical level you are.
what part of CH you are? I´m at the border to CH near basel on the german side.
as you think right the thermoswitch ( there is only 1 for both radiator fans ) is working fine.
fastest way first have a look at the fuse box if something is melted or burnt. also remove the relais and have a look at the connectors. if all seems ok then next to test is to put 12 V plus and minus direct to the fan and see if it will run or not.

 

I'll post this again for your reference -- these are the 5 TR stock fuse-relay panel terminals (in the horizontal white connectors at the bottom) that usually get fried (and the connectors have to be unplugged to see the trouble):

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Usually the HVAC Power terminal fries first, followed by the fuel pump terminals, and then the radiator fan motor terminals. If those others are all fine, and only one of your radiator fan motor connectors is fried = you would be the exception (wouldn't surprise us at all if you get in and find some wonky fixes/repairs have already been made to the others).

Try a search on "fuse-relay panel" in the Boxer/TR/M section for many prior threads and descriptions of your options to fix or upgrade to a different fuse relay panel solution (Guido's, G.T. Carparts, Scuderia Rampante)

 

and hopefully tell us ( may be with photo ) what you found - if you will find some. wish you all the best
and gradulation to your 1st ferrari - a real one with 12 cylinder

 

Alex, I had a similar issue on my 1986 Testarossa, except the right- side fan did not run. As I worked through the potential failure modes, I got to the fan relays and swapped the left and right relays to see if the problem just followed the relays. As it turned out, both fans then ran just fine. I swapped the relays back to their original locations and both fans continued to run fine. My conclusion was that the action of unplugging the relays and reseating same wiped the right relay and circuit board contacts resulting in good contact. BE EXTREMELY CAREFUL UNPLUGGING ANYTHING ON THE CIRCUIT BOARD AS IT IS OLD AND FRAGILE. EDoug

 

There are some diverging options on cause and consequence.

IMHO it's the fans (and fuel pumps) that cause an overcharge (actually rather an over-amperage) on the fusebox / circuit board. Changing fuse boxes or circuit boards is only curing the consequence not adressing the cause.

I've changed both fuel pumps and fans some time ago and have never had any issues with the fusebox again (I did change the relays). Parts are priced very reasonably. Part number for the fans is Spal Kühlerventilator 2330m³ saugend D315-D280 T=94 / VA03-AP70/LL-37A 12V

PS: As you live in central Switzerland you certainly must know U = R * I (Ohms law, which is the technical treason for my diverging opinion: At constant voltage the amperage has to increase if the resistance is increased in the old appliances).
PPS: Don't hesitate to reach out by PM

 

You have a whole different understanding of mathematics and physics

 

At a constant voltage, old electrical motors may need more amps to operate. This is because an increase in resistance or inefficiency within the motor will result in higher current draw to maintain the same level of power output.

According to Ohm's Law (V = I * R), where V is voltage, I is current (amps), and R is resistance, if the resistance within the motor increases (which can happen due to wear and tear, inefficient design, lack of maintenance, etc.), the current (amps) must increase to maintain the same voltage.

So, even at a constant voltage, if the motor becomes less efficient or more resistive over time, it will draw more current to compensate, resulting in higher power consumption.



Over to you @Steve Magnusson

 

Completely wrong. V = I * R means that if R goes up, the I goes DOWN at the same voltage V.

 

Sorry. I was using resistance with 2 meanings.

Meaning 1 (mechanical resistance):
In an old electrical motor the resistance of the components increases as bearings wear, magnets loose strength and [...], thus more torque is required to keep the motor running.

Meaning 2 (electrical resistance; Ohms Law)
If you need you need to produce more torque, you need more power. Assuming that Voltage is constant you need to increase current.

Common ground?

 

He must be thinking of heat

 

Yes, but your logic is still wrong. If the mechanical rotating resistance of the motor spindle goes up = the RPM of the motor goes down = the back EMF generated by the motor at that lower RPM is lower = the effective "electrical resistance" of the motor goes down = the current goes up at the same applied voltage. However, once a terminal is burned up, if that is the cause, it doesn't "fix" the the burned up terminal.

 

I have been fixing fans and fuel pumps and boards and measuring the loads in Testarossas since 1985. While it is true, sometimes a fan but far more often a pump in the process of going bad increases the load to the point it damages the connector and sometimes the board itself it is far more common by a large factor that the connector and board is damaged and the load placed upon them after repair by the pump or fan is normal. It was a terrible connector design. It had very little surface area and depended too much on its modest spring pressure to maintain contact. A standard 1/4 inch spade would have been far superior.

 

Ok. Let's agree to disagree then. In my universe electical motors draw more current as they get older. In yours not.

 

this only will happen if there are too much amps or bad connection that you may see in the night even some sparks. if it would be a problem of the motor to need more amps/voltage the fuse will burn

 

Part of the issue is, that as old electrical motors draw more current (in my universe) than specified, the surge of the current still is not fast enough to overheat the fuse and thus break the curcuit. This then leads to the melting of the connectors. Under specific circumstances this can result in fire.

A lot of the cars from the 80s and 90s have this problem to some degree. On Porsches of this period it's often the aircondition blower ....

 

No, I agree with you that an electric motor with more mechanical drag draws more current at the same applied voltage (and tried to explain why). You just keep using terminology that is completely wrong like: "more torque is required to keep the motor running". DC brush-type electric motors do not "require torque" -- they produce torque.

 

As we agree that there is higher current on old electrical motors, I continue to promote the pre-emtive swapping out of both fans and fuel pumps before replacing the fuse box. Contacts in the fuse box will have to be thoroughly cleaned as Steve pointed out correctly.

I've replaced the electrical motors on several cars from different manufacturers which had fuse box issues. It works, is closer to the factory spec and is more cost effective.

 

Very honestly: I don't know.

I'm quite confident that the details I gave are the ones we installed on my '89.

They still seem to be available on ebay.