How can I fix the heater which is blowing on full?

try this, which was for a similar problam on a Berlingo

http://www.johnandchris.screaming.net/berlingo_blower/berlingo_blower.htm

Jon
January 2009

hi had this problem on a 2003 xsara, its the module on the heater motor,(common fault on xsara) you will have to replace module on heater motor or do as i did and go to scrap yard and find another motor on citreon or pergeot ( which are the same) and replace the motor its only four nuts under the dash on the passenger side. if the warning light is on on the dash you will have to take it to an auto electrician to get the light off,

david
July 2007