audi A3 1.6FSi sport 2006 rear demister ,heated door mirrors not working

[uk174]

Evening learned people,

 I am hoping someone can shed some light as to where to look in my search to get my rear demister working. Initially the rear demister light was coming on when the switched was pressed but since I have changed the rear wiper motor the rear demister switch is not working ..not sure if there is  a link.

 Have checked the fuse along the side of the dash and that is ok. However when I put a multimeter across what i beieve to be the rear demister wires I get no reading.

 Not sure which two wires on the back csreen are for the demister as there are two sets of 2 wires and all seem to be connected or leading into some form of box on the rear tailgate.

I have only just found out that the door mirrors are not heating up too after reading a post saying that the two msy be linked

 Is there a relay that controls these functions and would getting the car read by a vcds shed more light onto this.

 Sorry for sounding like an ignoramus but I could really do wiith some help

many thanks in advance

 

 

[cliffcoggin]

Ir would be worth checking the continuity of all wires running up the rubber tube between tailgate and body. They have reputation for breaking.