Bradford

Fans are not running after engine is shut off. Where exactly are the fan(s)? What to check for? Don't know if the fan location is different on a n/a vs. a TT. Thanks

gonzilla

Oh Scott, what a shame. I'm sorry to tell you but your car is history. I guess I can do you a favor and trade you my 96 Carrera for it. Maybe, just maybe I can get it back on the road someday.

loubeer

The fan is in the left/top/back area of the engine and is the same fan used for heating/AC. After shutdown, the fan is controlled by thermostats/sensors and the fan will not necessarily be running - only runs when the temperature is high enough. The fan may come on intermittently as the temperature rises to scavenge heat out of the engine compartment. After @ 20 minutes, there is a "timeout" feature that prevents the fan from operating to make sure the battery stays OK.

Bradford

Mike - Thanks for the offer .

If I go on a drive with other cars similar to mine and we all shut our cars off, my car is the only one that the fans are not on. So the fan does not cool any particular part, it just draws heat out of the engine compartment?

JasonAndreas

With the ignition turned on the setting of the temperature mixing flaps (potentiometer on the CCU) controls the rear blower. If the flaps are closed (temp set to max cold) the rear blower is controlled by the temperature sensor in the rear ducting. 1st stage goes on at 45C and will turn off at 40C, 2nd stage turns on at 62C and turns off at 57C. If the ignition is turned off the rear blower motor will turn on the 1st stage for upto 20 minutes if the temperature rises above 75C and will shut back off when it drops to 70C. If you have an ohm/multimeter you can check the resistance of the temperature sensor (see image below).

0'C (32'F) 28.8 - 36.4 kOhms
25'C (77'F) 9.0 - 11.0 kOhms
50'C(122'F) 3.1 - 4.0 kOhms

You can check the general fan operation by turning the heat to high (on the CCU) and the fan speed to #4 (max). If there is a problem with the rear fan the front blowers will not operate with the heat on.

Bradford

As always Jason, you are a wealth of information. I will check into it this weekend. Thanks

Bradford

Okay, I replaced the temperature sensor and the rear blower resistor and the fan still does not go on after the car is turned off. Any other suggestions? Thanks

dcdude

So there are two electric cooling fans? This one in the rear directly on the engine and a second one that blows on the oil cooler up front?

Bradford's issue is all unrelated to the resistors up front, right?

JasonAndreas

You're positive that the temperature in the rear ducting is above 75°C?

Bradford

Am I positive, no. But as I said before, if I go on a group drive with other 993's, all of their fans are on when we stop, but mine isn't. The weather is pretty warm right now so I can only assume it is up to temperature.

Marlon

75 deg C is about 167 degrees F!