SEAT Toledo fan - 2nd request

Bren

Guest
SEAT Toledo SE 20V Auto. W Reg :confused::help:

I noticed the other day that the radiator cooling fan keeps speeding up and
slowing down. It seems to start doing this when the engine temperature reaches
70 degrees. The normal running temperature is 90! It appears to be putting a large strain on the electrics as the headlights become noticeably dimmer when the fan speeds up. It stops when I switch off. Even if I allow the car to rest for about 15 - 20 minutes to allow the engine to cool before starting it again, the fan starts to do the
same thing when I switch on the ignition before starting the engine. I have had this car a few years and know that this is not normal behaviour. Coolant and oil levels are fine. Climate control is not switched on but it appears to be working properly when I do switch it on. I took the car into a garage the other day and they were not able to diagnose the problem. The only time I have ever noticed this fan in the past was when it kicked in for a minute or so after switching off the engine in the summer when it was very hot. Now it seems to be on almost all the time but not at a constant speed – it speeds up and slows down every 4/5 seconds.
 

Muttley

Catch that diesel!
Mar 17, 2006
4,987
31
North Kent
I don't think there are many Mk.1 Toledos out there, which may be why you've not had much luck. If it helps, the car is based on the Mk.2 Golf/Vento.

The fans do take a lot of power, which is why you might see some effect on the lights, especially at idle. Shouldn't be very severe though, if it is maybe the earth straps need checking?

The only thing I can suggest is a look at the thermoswitch - assuming this setup has one. On the Mk.2 Toledo the fans are controlled by a simple thermoswitch in the radiator itself, so respond to radiator temperature. If the Mk.1 setup is similar then I'd check that thermoswitch first.
 

Bren

Guest
It's a Mark 2 Toledo, manufactured from 1999 to 2005 /6 I think. Mine was first registered in June 2000.
 

Bren

Guest
I read the info on the Nime website. The problem is that my fan comes on when the air conditioning is switched off. It seems to switch itself on when the temperatire gauge reaches 70 degrees.
 

Muttley

Catch that diesel!
Mar 17, 2006
4,987
31
North Kent
Thermoswitch mounted low down on the nearside edge of the radiator. Controls fans according to radiator temperature alone. Should switch as follows:

Low speed
On 92-97°C, off 84-91°C
High speed
On 99-105°C, off 91-98°C

Remove and test to see if it is doing what it should do. The coolant will fall out so be prepared to replace it.
 
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