I have a 1996 miata. Can anyone help? Started overheating. Put a different fan motor in it. Still over heating some. Took fan out then back in. Tried driving it. But would not idle. Ran at 2000 rpm. Unplugged the fan and it came back to the right idle. Then plugged it back in and it stayed at the right idle. What would do that?

 

The computer can tell when its unplugged & will raise the engine speed to circulate coolant faster to try and compensate.

Is it loosing coolant?
Does the cooling fan actually work when it gets hot?
Are both radiator hoses hot when it overheats?

 

I will check on that.