Cooling fan doesnt come on unless a/c is engaged

You most likely need a new ac compressor

The radiator fan should turn on when the a/c clutch engages as this is designed to increase the cooling of the engine as the a/c increases the engine loading. But the compressor clutch should stay engaged as long as there is need for cooling, and disengage/re-engage as the temperature control calls for cool air. The radiator fan will shut off IF the engine temperature is cool enough to do so, as it is regulated by heat, as well as the A/c override.

If your air conditioning is not cooling the car and the clutch is simply disengaging prematurely, have the temperature control and relay checked for proper operation. Also have the refrigerant level checked to assure there is adequate refrigerant in the system and no leaks. My first bet would be the relay or the thermostatic temperature control under the dash.

Sounds like the fan's thermostat is bad. You will need to trace out the wire to the thermostat and replace

Hi Columbia,
If the fan operates with a hot wire and you've replaced the relay, try the sensor.

• On your vehicle there will be three sensors for the cooling system. All will be fitted either into the cylinder head or close to the thermostat housing.

1. Takes signal to the gage on the dash instrument cluster and is a single cable.
2. Will be the cable that control's fan operation (This is the one you want)
3. Is a double cable and takes signal to the management system

To test which of the single cables is which, when grounded the heat gage will go full hot on the instrument panel.The other should engage the fan....Unless the relay is a normally open, in which case the fan will run as soon as you disconnect.
Once this test has been confirmed, loosen the sensor and replace it.
Remember to top up with the required coolant before start up.
Leave the engine idling to gain fan operating temperature and check that it engages.
Regards Johngee10

So your cooling fan isn't coming on???? Thats either a fuse or your relay.

you have a problem with the cooling fan not cutting in ,if the ac is engaged it should put the fan on if it doesnt then something could be up with fan motor ,but most likely its temperature sensor which is not expensive

I have the same car. The cooling fan activates at 227F. Only one fan will engage at this temp, the other one[closer to the A/C compressor] won't engage unless the A/C is working. Try charging the system with half a can of refrig. It'll be tough retrofitting to R-134A, the LOW PRESSURE connector is under the air box pointing sideways about an inch from a large bracket. Try and find a 90 degree adapter of some type and go from there.

Bring the vehicle into a repair shop the technician has to duplicate the situation before he /she can conduct testing. I don't think your cooling fan is the problem . I'm leaning towards engine main relay.(located under the dash board) contacts getting hot and once you turn off car there is no ventilization inside the vehicle ( a/c air blowing on relay) to cool it down. The only
draft is coming from cooling fan to cool off its contacts. Pretty soon you'll have longer wait periods before you can start the vehicle . Unless you live in the Artics.lol

the cooling fan prabably isnt turning on. Next time turn the AC on when this happens. The AC should autmatically turn the fan on. If you dont see the temp going down then the fan isnt turning on.

I have a 1996 SL1. The cooling fan automatically turns on when you turn the A/C on. If the A/C is off the cooling fan will only come on when your temperature gauge reaches almost 3/4. I've had my car for 13 years and this has always been the case.