ac control unit for climate control.

[mister1000]

I have a 1992 525i approx 90,000 miles,150 k
Car runs flawlessly,have a bit of a overheating issue,but new waterpump installed and thermostat coming tomorrow.Hope to resolve this issue with a good flush and burp .
Anyway the real issue I have right now concerns,the climate control system.In december I returned from a 50 mile road trip just before christmas,pulled into the garage and could not turn the vehicle off,at all.
key off ,gages would die ,fan would stay running, radio playing and the car keeps running,on , off on off key now nothing,what i should have done was pull the fuel pump fuse and let the car starve itself out but i didn't.Instead i had a stupid brainstorm to pull the plug on the computer under the hood,well as soon as i did that ,the smoke started rolling from the defrost grills inside the car,great I really screwed it up now.Well car shut off now no problem obviously,and after reversing my stupidty and plugged the computer back in the car started and stopped no problem except AC is toast,and Diagnostic in dash dimmly lit and annoucing CHECK CONTROL.TIme for the shop,Take it too a reputable garage who is know for working on BMW ,mercedes,Porchse ,a few in the parking lot.
They diagnose the Ac control unit is fried, and they dont even know if they can get the part,I phone local bmw shop 60 miles away,and the techy on that end doesnt seem to know what the hell i am talking about
this part.After two weeks of having my car they jury rigged the heat so i had defrost and heat,but no ac or control,this was one day before christmas ,wife is freaking, got no car,presents to buy etc.I took the car
home and it has run flawlessly until this heating issue lately.
During this time period i reseached the net looking for this part Ac control unit ,not only the part but the actually plugs i needed as well,they had a serious meltdown.Not much info out there on this animal.
But finally found parts on the net in the order of 850 US ,well to a canadian boy thats about 1100 canadian.Wooow
Did some more research and managed to hook up with someone on ebay
who was parting out a 1992 525i smashed bmw,And i managed to get my hands on the Ac control unit and all three plugs for the wiring harness, out of this car for 180 bucks canadian.So far so good.
I installed it yesterday boards look identical,case part number identical,
chips all the same on boards,wire colour coding for identical for plugs into harness.The only difference I found was a number on the boards ,the part number (i believe) ,with a L designation versus my original K designation,thats all.Now I noticed on the net for the new boards ,they come UNCODED.SO I guess these boards need to be coded to the vehicle?????????Is that correct???I found under the fuse panel lid
a code number corresponding to my ac system id
IHKR III code 5. under the vin number.I phoned the fella I got the ac control unit from and over the phone, this car says 3 for the code,I hope and not III.Reason I ask is I havent tried the ac yet to see if is working i have been waiting for the thremostat to show up first and resolve the overheating issue first,before going down that road.Is there any way to manually enter this code into the operating system or is it a bmw dealer thing.Any info would be appreciated.
I havent turned it on yet but i did try the rear defrogger which hasnt worked since december and it appears to be working.BUT on the way home from work tonight,everything on the dash lit up first abs,then check engine,rpm 0,I'm going down the road 2 blocks to go to my house,trans program now,I can tell the tranny feels like 4th from standstill,get home shut car off,windows wont roll up ,sun roof open ,thunderstorm called for tonight,jeez what else can go wrong.
Car wont start,feels like dead battery now,pull the seat,slapped a trickle charger on the battery,left it for an 2 hours,hooked up battery,car fired right up everything back to normal,but i said screw it unhooked the AC control till I get more info.Any would be appreciated on this matter.I know you must be thinking ,jeez look at the size of this post and his first,
I promise not to blat to long on next one .THankx mISTER

[mister1000]

well everything is back together and thank god no smoke,now the question is do these ac control units have to be coded to the car,a simple yes or no would suffice,i have all lights working on control panel,compressor working but all hot air blowing from vents,and i dont hear that high pitched wine I used to hear before the unit fried originally.thankx for any info you may have.Mister