Hello, 

I decided to do AC evaporator cleaning but I can’t really find the drain hose for the AC system under the car. My only info about this is in the interior of the car which is located under the passenger side (see photos).
My goal is to find the external drain hose to feed the little cleaning tube with the ac cleaning agent. 
 

now, I don’t know witch method is the best to clean ac Evap, but my best bet at the moment is to follow this method. 
 

P.S: I looked under the car for the drain hose but no luck there. Maybe it’s hidden or too short to find it in engine bay. 

Hi, did you manage to figure this out? I'm in the same situation wanting to clean the AC by feeding the cleaning tube up the drain pipe. From a video on YouTube for a mk7 golf, I believe the drain pipe is located under the foot rest (right hand drive car). When I have some free time I'll take a look on my mk3 RS245.

13 minutes ago, wokka said:

Hi, did you manage to figure this out? I'm in the same situation wanting to clean the AC by feeding the cleaning tube up the drain pipe. From a video on YouTube for a mk7 golf, I believe the drain pipe is located under the foot rest (right hand drive car). When I have some free time I'll take a look on my mk3 RS245.

Hi. Yes indeed the drain hose is located behind the foot rest (on right hand drive cars). WARNING: i strongly advise you to not try to pull off the tube because there is a risk to rip off the tube and then you will another problem to solve.  I did not find an external drain tube (i believe it is hidden behind the heat shield of the firewall in engine bay) but instead i removed the blower motor inside the cabine and it is relatively easy to feed a cleaning foam tube inside the big gap and do the job. 

For better results, use product the one that has omnidirectional holes on the tip end of the tube to apply the cleaning agent to the entire surface. 

TIP: use your phone camera to see how far you have to feed the tube and the position of the evaporator core. 

I hope the description will help you. If not ask me for further assistance. 

Thanks for the tips. Hopefully I can give it a try on the weekend.

50 minutes ago, wokka said:

Thanks for the tips. Hopefully I can give it a try on the weekend.

No problem. always happy to help. One last thing. to remove the blower fan it is extremely easy. just unplug the connector and twist the fan anti clockwise and it's off.