Cooling Fans From HELL!!!!!

**Merceded** · 09-12-2008 07:07 PM

Ok so this is my problem....

The fans keeps kicking in once the car has been off for a few minutes and it keeps going, switching from low speed to high speed until it drains the battery, and when I use the key fob to lock/unlock the car, it seems to stop the fan for a couple of seconds, and then it starts again. And the fans turn off when I switch the key to the on position without turning the car on.

The car is not overheating, nor it has any heating problems, the fans work normaly once the car is on. And the temperature gauge reads normal all the time, nothing erratic or out of the normal.

I ran the Vag-Com and no codes at all

I have a 2002 Audi A4 1.8T Quattro 5spd (8E B6) With an APR Chip and GFB BOV.

This is what I have gotten from other sites and people what it could be, but i dont know where to start or if it even applies to my car:

1. AC/Electrical Fan Relay #53 (Part# 141-951-253 B) that its staying open once the car is off.

2. Air Condition Pressure Sensor faulty

3. Thermostat Switch

4. Thermal Fan Switch

5. Cooling Temp Sensor

6. Cooling Temp State/Sender

7. Fan Control Unit/Module

Where should I start? And where are these parts and switches located in the engine/car. Or what else can it be?

Please HELP!!!

**cjonesgo** · 09-12-2008 08:11 PM

Erratic fan can be caused by the "rear coolant flange/temp sender" failing. From what I have heard and experienced, it is typically turning the fan on even when engine is cold. I've not heard of it running the fan to the point of running a battery down, but maybe I just caught mine in time. $11 part at napa and a real pain in the ass to replace, but easily accomplished in an hour. Pretty sure there is a DIY on a4mods.com replace with the upgraded Green one.

Mine threw a code when it failed. Hope it ends up being a simple fix, good luck!

**nvr_follow** · 09-13-2008 09:48 AM

I think I heard others with this problem say it was the fan control module that was faulty...I see you have that listed.

**aaronz** · 09-13-2008 10:01 AM

Hmmm... I hate the issues where there could be 1 million possible fixes. You just made me realize that my fans never come on when I turn the car off. I don't have any codes and no issues overheating, but when i shut the car off, its off, no moving parts or noises of any kind. Wondering if I have a problem....?

**Merceded** · 12-07-2008 09:43 PM

FIXED! The ECU storage cover was cracked and water was leaking during the rainy days, which summerged the Relays under the ecu and damaged it, I replaced the damaged ones and WhAM! all was back to normal. But I fixed and sealed the ecu cover box.

**onceover** · 12-07-2008 09:48 PM

Originally Posted by Merceded

FIXED! The ECU storage cover was cracked and water was leaking during the rainy days, which summerged the Relays under the ecu and damaged it, I replaced the damaged ones and WhAM! all was back to normal. But I fixed and sealed the ecu cover box.

that was going to be my suggestion.

**afmafia** · 12-31-2008 06:47 AM

99 percent of the time a fan running all the time will be the coolant temp sensor.

**bmags88** · 12-31-2008 07:50 AM

I just fixed mine last night and it was a cracked ECU coverletting water in and damaging the relay. Got a new relay and cover for $80 at the dealership!!