M535i (E28) auto gearbox problems

Hi all,
I hope someone can shed some light on this problem as its got me! I recently bought a 1987 M535i with the switchable automatic gearbox. I
have discovered that when the car is cold it doesnt want to change gears properly. I think it manages to drop into second gear but refuses to go into third although at about 2500rpm there is a second of hesitation as if it was going to change but decided not to. If its in sports mode it seems to cope with better as doesnt need much to get it to 40mph until its warmed up and then it behaves and changes gears as normal for the rest of the journey.
The other weird part is when I come to a stop if I engage neutral it still stays in drive while this other problem is happening, but again when its warmed up it works fine. Any ideas anybody please as I have no idea where to begin??? Im thinking maybe an electrical fault as the wiring in the car was less than perfect to start with and I did have fuses popping and even the heater fan has died although I have a replacement ready to fit.
Thanks,
Dan.
P.S. I can also be contacted directly at snipped-for-privacy@yahoo.com
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Oil low, contaminated, changed for wrong grade in box?
Microswitches in box broken, clogged up etc.
In sport mode the gearbox is essentially hyraulic, but in economy the electronics run it.
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When you move the gear selector check the dashboard lights "agree" and come on correctly. My 635 had play in the gear selector, I could select drive but not have the dash light D illuminate. This gave me a twilight zone where all sorts of odd things happened, none of them good!
Failing that the next step is to try a new filter screen and a fluid change.

Try cleaning the contacts to the fan first, I've had a few "die" because of nothing more than dirt. Easy fix :-)
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Email: snipped-for-privacy@unixnerd.demon.co.uk, John G.Burns B.Eng, Bonny Scotland
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My E39 holds on to second gear when cold at town speeds. This is designed in to get the engine (or more likely the cats.) up to temperature as quickly as possible. My previous E34 did the same too - most noticeably that it wouldn't select 5th gear - if starting from cold and going straight on a motorway - until warmed up.
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*Funny, I don't remember being absent minded.

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
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I suspect that's a (good) feature of the five speed boxes electronics. I doubt the older four speed box is that clever :-)
--
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Email: snipped-for-privacy@unixnerd.demon.co.uk, John G.Burns B.Eng, Bonny Scotland
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