My Blower has gone MAD. Please HELP.

[samsx5]

Hi Everyone. I have had my X5 for about 2 months now. Due to work my wife has been driving it. I got in the other day and noticed that the blower/heater has gone rather mad. No matter what I set it on it just does as it wants. ie..set on first/lowest setting over a small journey it can be either blowing me out of the car or not on at all, fluctuating between all the blower ranges. The heating setting work fine its just the blower that has a mind of its own. I have a 325 with exactly the same system in which works fine so its not me lol.

X5 4.4i 2000 with LPG Conversion (and crazy blowers).

Thanks for reading, hope there's someone that can help me with this as its driving me mad.

Tony