I have 1999 Audi A4 Avant 1.9 TDI. Usually when turning the climate control to full auto mode (therefore turning on the air con) the auxilary fan turns on in the engine bay and the air becommes cold. Recently the fan is turning on for 30 seconds and then shuts down (usually it stays on when the compressor is on). The air is not cold and also I have noticed there are two metal pipes that I think are connected to a gas cylinder underneith the drivers side headlight cluster. These pipes usually get so cold that condensate form on them. They now stay at normal temperature.
Due to the extreme cold I have had the econ mode on for a long period of time....does the gas just need recharging? I have only had the car for a year and don't know if it has ever been re-charged.

Thanks for your help

Cars & Trucks - Audi - A4 - 1999 Audi A4