I have never seen my engine compartment fan on. When is suppose to turn on. I had a taco wing put on 6 years ago and I wonder if it wasn't hooked up right. How can I test it to see why it's not working.

I'm going to do 1999porsche911 radiator fan mods right now and I saw the engine compartment fan mod also. I want to keep the engine cooler on the track.

 

If you have a durametric you can actually turn the fan on and off via a laptop to check that the fan works. I don't know the exact temperature it is supposed to come on nor do I know where the temp sensor is. The manual just says it comes on when it is hot enough in the engine compartment.

 

I have a durametric. But how do I go about activating the engine compartment fan with it? Thanks in advance!

 

On the new version of the durametric there is a section called "Actual Values." Under that section you can do things like turn on/off your front or rear cooling fans, check your gauges i.e. putting the fuel level gauge at half or full tank etc...

 

I will try it out, thanks!

 

My front bumper fan are almost always on.. is that normal ? they are pretty loud, so I assume they are at full speed...if there is such thing as lower speeds for those fans

 

There is supposed to be a low speed and a high speed...
I believe under most conditions the fan will run at high as long as your A/C is on.
I forget what conditions they run at low.

 

there is a wire attached to 3/4" plug on the top right of the engine. unplug it and the fan will come on.

 

This is from LOREN of renntech

"Electric fans (radiator fans)
There are two radiator modules installed in the front of the vehicle (on the left- and right-hand side). These radiators are each fitted with an electric fan. They can be operated at two speeds and are activated by the DME control unit whenever the following conditions apply:

Electric fan, speed 1
(Ground to DME control unit, terminal 35)
Coolant temperature higher than 96.75° C or air conditioning switched on.

Electric fan, speed 2
(Ground to DME control unit, terminal 36)
Coolant temperature> 102° C or air-conditioning fluid pressure switch closed (coolant pressure> 16 bar).

Note: The electric fans for the radiators are only triggered when the engine is running!
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Engine Compartment Purge Fan
To reduce the temperature of the engine compartment, a fan actuated by the DME control unit is installed under the ventilation grille of the engine cover.
If the fan is active, fresh air is fed into the engine compartment. The fan can only be actuated 100 seconds after the engine has been started.

Functioning
1- With engine running or ignition on:
If the engine temperature is higher than 102° C and the engine compartment temperature is higher than 60°C, the engine compartment fan is switched on for 30 seconds by the DME control unit and the engine compartment is thus ventilated.
2 - Engine compartment fan if vehicle is stationary and engine is switched off (after-running of control unit):
If the engine compartment temperature is higher than 60° plus C when the engine is switched off (ignition off) or if the engine stalls (engine speed: 0 rpm), after-running of the DME control unit lasting 20 min. begins. The DME relay remains active.

After-running of the fan continues until the programmed time has expired (20 min.) or until the next engine start after which the engine runs for more than 100 seconds. If the engine compartment temperature is higher than 84.75° C during after-running of the control unit, the engine compartment fan is started and runs for 30 seconds.

If, at the end of the operation period (30 seconds), the engine compartment temperature is still higher than 84.75° C, the engine compartment fan is started and runs for another 30 seconds, etc. If the temperature now drops below the threshold (84.75° C), a polling pause lasting 10 seconds occurs.

Note: If the engine temperature has not dropped below 80.25°C after the engine compartment fan has been running for 25 seconds, a fan fault is registered and the coolant level warning lamp is activated (flashes)."

Quoted from the MY1999 Carrera (996) Service Information Book - available here for viewing by our Contributing Members.
Loren
RennTech.org
PCA member since 1978
My Mods in the Registry · My Blog

 

few yrs ago i installed switch to manually control radiator fans per posts here- very easy and it keeps my temps a bit cooler when in traffic- with fan on it runs a hair to right of / 180 line, w/o fans on temp is just to right of middle of 0 in 180-
i just put in a switch for engine fan this week- a breeze once i figured out which relay is #8- that controls eng fan. looked at wire diagram found at RT or RL site to determine correct relay to tap. various posts about this also but it didn't give specific info which was correct relay as was done for the rad fans.