Engine Blower Fan

[bmohr]

I have confirmed(i believe) that I have a dead engine blower fan. I disconnected the engine temp sensor plug with ignition on and no workie workie. How can i check the fuse or relays to make sure they are not the culprit before swapping in a new fan? I don't have much experience working with those relays, nor a relay layout/guide. TIA

1999 C4

Edited May 8, 2009 by bmohr

[1999Porsche911]

I have confirmed(i believe) that I have a dead engine blower fan. I disconnected the engine temp sensor plug with ignition on and no workie workie. How can i check the fuse or relays to make sure they are not the culprit before swapping in a new fan? I don't have much experience working with those relays, nor a relay layout/guide. TIA

1999 C4

Get the car to operating temperature and if the the plug is disconnected from the sensor, the fan should be running. It should tunr off when you reconnect it. Relay is behind the driver's seat under the shelf carpet in the silver relay carrier.

Or you can ground the relay (#8) to test if fan motor is functional.

Edited May 8, 2009 by 1999Porsche911

[Loren]

I have confirmed(i believe) that I have a dead engine blower fan. I disconnected the engine temp sensor plug with ignition on and no workie workie. How can i check the fuse or relays to make sure they are not the culprit before swapping in a new fan? I don't have much experience working with those relays, nor a relay layout/guide. TIA

1999 C4

It is rare for the engine purge fan to come on at all.

Mine only comes on after I come off the track while I am idling during cool down.

"Switch-on conditions for engine compartment fan (this fan pulls air into the engine compartment) The engine compartment fan is switched on when the engine compartment temperature is > 176 degrees F or the coolant temperature is > 216 degrees F.

After-running of engine compartment fan

If the ignition is switched off and the engine compartment temperature is more than 140 degrees F, the DME control module remains in readiness for another 20 minutes. During this time, the engine compartment temperature is retrieved every 10 seconds. If the engine compartment temperature is > 185 degrees F , the engine compartment fan is switched on for 20 seconds. If the engine compartment temperature is still > 185 degrees F after this time, the fan remains on for a further 30 seconds."

[bmohr]

gotcha, tu. I finally found the mysterious silver relay box! :)

[bmohr]

okay, thanks for the details loren and 1999. I took off the front bumper this weekend and blew out the rads. Some debris, but not terrible. Put back together and it still seems to be running on the hotish side. 101 c intown driving on a cool morniing. And the engine blower fan did come on when i pulled the temp sensor connection off when car was up to operating temperature, and then turned off when i plugged back in. So everything seems functional. I think i'm going to wire up the engine box fan mod and see if that helps if not then it's on to chasing tails for a bit! lol