2003 Volkswagen Passat Cooling Fan Control Module

TIMOSENCO

MEMBER
2003 VOLKSWAGEN PASSAT
6 CYL
FWD
AUTOMATIC
90,000 MILES

The radiator fan on my 03 Passat V6 always comes on. The other fan (for the AC) does not come on when the AC is turned on. Is this fan suposed to come on as soon as I turn on the AC or only when needed by the cooling system? The Cooling Fan Control Module has already been replaced.

Also my radiator has a slow leak. Beacuse is leaking, I'm not putting coolant on it, only whater. Does having water instead of coolant on my radiator intervene with my AC or Heater temperatures?

1 Reply

MATHIASO

MECHANIC
1,209 POSTS

Hello timosenco

You should replace the radiator, flush the system, and add G12 coolant.It is easily identified by its red color and is mixed with distilled water at a 50/50 ratio on all USA models and a 60/40 ratio for all Canadian models.
Both fans should come on when the A/C is on.

the cooling fans will operate for a short period of time when the engine is shut off if the coolant is above a given temperature. This prevents over heating, helps with hot restarts, and in extreme ambient temperatures, prevents a vapor lock condition and having plain water in the system is not good.
if fixing the radiator does not solve the problem,check the relay,the AC switch and the fan motor