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Discussion Starter · #1 ·
I am fixed my first MR2 MK1 and both of my radiator cooling fans are not running. Could anyone give me some clue how to fix it? i.e. where is the fan fuse located? What are the common issues and how to ping pint the issues? Thanks!
 

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Thanks! Does the fan come on when I started the car or it will run until coolant reaching certain temperature? The relay in above image May related to the cooling fan in the engine bay only.
 

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the fan will come on when the temp sensor top left of above pic gets up to temperature. Check relay, check sensor, also check thermostat in engine. if its stuck open it may never reach proper temp depending on your location.
 

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Discussion Starter · #5 ·
Thanks! How can I test the radiator fan? I assume if I unplug the radiator temp sensor, the fan will stay on once I start the car, right?
 

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If you disconnect the radiator temp sensor the fans should come on at full speed. Also if you disconnect the AC overpressure sensor. The fans should also come on when the AC compressor is engaged.

Aside from AC use, the radiator fans rarely come on. They are triggered by radiator temperature, not coolant temperature, and the car has a vast excess of cooling capacity. In my experience, I needed to idle the car for a while in hot weather before they were needed. Many people have complained that their fans do not work when in fact they had just never been triggered.

I will also point out that the cars with AC have a very complex dual speed fan controller. The fans serve both the radiator and the AC condenser, and the control function is integrated in the AC controller. If you need to actually troubleshoot this, get the BGB and go to the AC section, where there is a clear schematic of the fan control wiring. Otherwise, it will seem to be pure nonsense.
 

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Discussion Starter · #7 ·
Thanks for the information. The previous owner of my MK1 took the AC off, this is why I think the fan shall be on all the time since there is no compression or pressure anymore. I will take a look of the service manual.
 

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... The previous owner of my MK1 took the AC off...
Well, then, who knows what you have actually got.

The right way to remove the AC is to short the connector to the overpressure switch, and leave the AC controller alone. That should remove the failsafe AC function, and the engine cooling should work normally. The fans should come on at low speed when the radiator temperature reaches the first set point, and they should switch to high speed if the temperature reaches the second set point, or if the sensor is disconnected. Remember that you may need to idle or drive slowly for a while before you reach even the lower set point.
 
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