Hi Allison,
I just fixed the "blower stuck on full-blast all the friggin' time" problem on my 2000 Xsara... by:
1) dismantling the blower assy. (see Haynes),
2) drilling out the two TO-3 power transistors that control fan speed (of which one was internally shorted) and
3) replacing them both, they are darlington pair PNP power transistors with standard TO-3/ PNP pinout... (case is Collector, pin 1 is Base, pin 2 is Emitter)
Also i added a big diode (20A+) across the fan to take the inductive transient that fried the transistor in the first place...
I could just have changed the whole blower assy, but this fix set me back about 12euro, compared to the crazy prices citroen wants for the whole blower :)
BR,
John
John Smythe, April 2008