The cooling fans don't operate as they did previously seasons after a belts, waterpump, thermostat change.

The fans used to cycle through an on/off process. The fans would click on when the guage hit the 12 o'clock position and turn off when the guage hit the 10 o'clock position. The process would repeat every few minutes in the heavy suburban traffic in this area.

But now the fans turn on at the 12 o'clock position but doesn't cool below the 11 o'clock position. The guage sits at 11 o'clock and the fans run continuously to hold it there until I turn the car off.

What is the correct operation? Will it damage the fans to run continuously?

1985 early 944 Chicago area, temps in the upper 70s

 

Perhaps you still have some air in the system after changing out the thermostat. Re-bleed the system.

How does it operate at highway cruising speeds? The same as before?

 

It does not operate the same as before at highway speeds. The fans used to shut off at a highway speed. I assumed that was because the continuous flow of air would cool the radiator. Now the fan will run continuously once it starts and doesn't fall below the 11 o'clock position.

 

What does it mean if I have steam that comes from the bleeder plug when the plug is closed?

 

It sounds like you have a leak.

There is supposed to be a sealing ring under the screw plug. Do you have the sealing ring under there? Try flipping the ring upside down and see if it will seal better. Only change this with the engine cold and be sure that the expansion tank cap is on.

I also think that you have air in the system still. It can be a real pain to purge all of the air out sometimes. Never remove the bleeder screw with the expansion tank (radiator) cap off it will only allow more air into the system. Also be sure that your heat controls in the cabin are fully opened when bleeding.

 

I have a 87 model where the cooling fans will run continuously if the battery is connected. I swapped out the relay with another one (from an 85-1/2, but the diagram looks the same) and the problem persists.

My guess is the only other thing left to swap would be the actual temp sensor, but somebody please chime in if there's something else I'm overlooking...

Thanks,
Denny

 

Unplug the wires going to the temperature switch. In case you didn’t know the switch is in the radiator. If the fans go off with the switch unplugged then it should be the switch that is the problem. If they keep running then look elsewhere.