Cooling problem
 

Hello

I noticed My car (1990 928 s4) was running close to the 190 (3rd bar) lately. When I checked the fans to see if they were running, they would (both) go on at the same time a little below the third bar. They would both go off then. When I put the AC on they both went on again.

Question: Shouldn't one of the fans stay on when the car is that hot?

Question 2: Does anyone know the sequence of the fans what temp they are to go on?

Question 3: Any ideas as to what may be going on here?

Any help would be greatly appreciated

Jeff