Probably cost too much in a garage if trying to save a few bob .I have found this which saves me trying to put in words ,
Astra g heater matrix / coolant shut off valve .
if your heater feed pipes under the bonnet going through the bulk head behind the engine to the right are hot then your problem is almost always the heater shut off valve which is very well hidden behind the heater unit inside the car.
this is out of view and has two wires going to it which powers a small motor with 12volts to close the valve and reversed polarity 12volts to open the heater water flow valve.
these two wires are part of the smaller wiring loom/plug on the back of the dash heater control panel, from what i can remember as you look down behind this panel it is the second and third wire on the smaller plug BUT PLEASE CHECK FOR YOUR SELF BEFORE PUTTING 12VOLTS DOWN IT AND DON'T FORGET TO UNPLUG IT FROM THE HEATER CONTROL UNIT!
all you need to do is feed it with 12 volts and reverse the polarity, you should hear the motor turning, when it stops your valve should be in the open flow position and you now should have hot air READ ON!!
You could get a wiper motor and linkage complete from a scrapyard cheap and this link explains how to replace (2002 madel but probably the same )
http://www.justanswer.com/uk-car/2b2x6-change-wiper-motor-linkage-2002-vauxhall.html
Motor on e bay (IF fault is internal)
http://www.amazon.co.uk/Vauxhall-Astra-98-04-Windscreen-Wiper/dp/B00B2M53O8
Posted Nov 24, 2014 (9 years ago)