E34 A/C Strange problem/Cabin filter??

[shogun]

I assume your problem is not the cabin filter, that is maybe a problem of the control panel or the IHKA control module behind the center console.
As you talk about MOT, you are probably from the U.K. and that means right hand drive, that makes it a bit more complicated to replace the cabin filter, as the steering column is in the way. U.K. car spec cabin filters are special, here you can see how it is replaced on a E32, basically same procedure on the E34 http://www.meeknet.co.uk/E32/Microfilter/Index.htm
A 1995 model has a cabin filter.

Here is the pinout of the IHKA control module for a left hand drive car, so when I say driver side in that link, on your car it is passenger side http://www.bimmerboard.com/forums/posts/648300/
http://www.bimmerboard.com/forums/posts/427753/
http://www.bimmerboard.com/forums/posts/426626/
resolder the IHKA control module http://www.bimmerboard.com/forums/posts/400077/
http://www.bimmerboard.com/forums/posts/220273/

[siarach]

I assume your problem is not the cabin filter, that is maybe a problem of the control panel or the IHKA control module behind the center console.
As you talk about MOT, you are probably from the U.K. and that means right hand drive, that makes it a bit more complicated to replace the cabin filter, as the steering column is in the way. U.K. car spec cabin filters are special, here you can see how it is replaced on a E32, basically same procedure on the E34 http://www.meeknet.co.uk/E32/Microfilter/Index.htm
A 1995 model has a cabin filter.

Here is the pinout of the IHKA control module for a left hand drive car, so when I say driver side in that link, on your car it is passenger side http://www.bimmerboard.com/forums/posts/648300/
http://www.bimmerboard.com/forums/posts/427753/
http://www.bimmerboard.com/forums/posts/426626/
resolder the IHKA control module http://www.bimmerboard.com/forums/posts/400077/
http://www.bimmerboard.com/forums/posts/220273/

Thanks Shogun,that gives me someting to go on