Recently had a problem with the heating in the car. Too hot or too cold even when temp was altered. Noticed the same thing with the GS I bought off Dean. Found the problem on Saturday, there is a black plastic pipe that fits onto the back of the Heating/Air con controller. This was off since I removed the gauge pod some time back. This pipe is used to draw air over the temp sensor in the controller.
Some of you guys probably already know anyway but thought I should post the info anyway.