Trying to get some A/C love plz help

[tintrx]

I'm trying to get my Air conditioning in my 1988 e32 to cool but my heater valves are staying open and letting coolant into the heater core. I checked for 12v at the heater valves, but it's not recieving signal. What do I need to check now? Also, without knowing if it was bad or not; I changed the control box in the dash on the advice of a mechanic friend, but it didn't change anything. Please help if you can. Much Thanks.

[shogun]

Maybe a broken wire, check the wires from control panel to heater valves, wiring diagrams are here
http://shark.armchair.mb.ca/~dave/BMW/e32/

also check on both sides of the IHKA control panel if the plugs are interted correctly, the control modul is farest behind the center console. Each side 2 plugs.
Read this, same issue
http://www.bimmerboard.com/forums/posts/690327

[tintrx]

Shogun, I Checked out those pin connectors from the IHKA behind the dash. Everything looked ok and in tact I'm going to check for signal once I get the wiring diagram downloaded(Still on dial-up), but while I'm waiting; is there a way to bypass that connection and replicate that signal another way to see if that truly is the problem?
Thanks again for all of your help.

[shogun]

how did you check 12V at the heater valves? the voltage is pulsating, that is not that easy to check. That is not a frequent voltage.
checking the heater valves
From ignition key position 1 (radio can be switched on) the heater valves get 12 V.

As they get only impulses the usual method to test with a digital multimeter (DMM) is limited, as it always only shows the middle/average value.
Switch the thumbwheel on the IHKA control panel to 28 degree C (max), then the +V line should be interrupted/cut off to the heater valves. At minium 16 degree C. ground/mass is fully on the valves, so that the valves close completely to interrupt the water/coolant flow thru the valves.
Best way to test is to use one of the old style test lights (cord test light) with the thin pin to pinch thru the isolation of the wires of the heater valve wiring. With this way of checking one can test if the problem are the heater valves or the control panel/module.
At max. 28 degree C. the light should be fully/always off, at 16 degree C minimum temperature the light should be fully on. In between 16 and 28 degree adjustment the light should blink, but in different intervals depending on the adjustment. Best is to switch the blower fan to max also, as otherwise the heater valves are adjusted automatically by the system, and the blinking frequency is reduced.
There are more simple ones with only a bulb inside, but I use this one, can even test the ignition cables
http://www.atu.de/extern/gfx/artikel/FS1_/FS1133_L.jpg

And remember, the driver side thumbwheel is the master thumbwheel. If that one is full on highest or lowest temperature (that means over the clicking sound=emergency position, see owners manual) the driver side thumbwheel overrules the passenger side one, pass can be adjusted to whatever you want, it does not matter, only the driver side thumbwheel for temperature adjustmax in max position.

[tintrx]

Shogun, As you recommended; I checked my output voltage with a test light (no Joy) No change in voltage either way. What's next; remove the IHKA module and have it resoldered? If so, is there an easy way to get that module out besides removal of the whole dash? Not looking forward to the fun.

[shogun]

IHKA module I would say is next. And that is not that difficult to remove.
It sits next to the sword. But on each side, driver side and passenger side there are 2 connectors. These you have to get out first, so just remove the carpet cover on each side of center console (1 screw) and then you see it, it slips out then to passenger side, but before you have to release that small plastic clip on passenger side, but that you will see when you have removed the cover.
Some info:
http://www.bimmerboard.com/forums/posts/426626/
http://www.bimmernut.com/forum/showthread.php?t=37062

then I have the best instruction for you, >50 pages IHKA training manual for technicians.
understand German?

Even if you do not understand the German language, read it, ir explains in detail the complete system, testing data for the temperature sensors, how the flaps move depending on the car speed and so on.
Klimaautomatik IHKA : http://www.e38.org/e32/klimaautomatik.pdf



drawings etc, so you will understand the system better.

http://bmwe32.masscom.net/johan/ihka/ihka.html

here I posted some pics of resoldered module
http://www.7-forum.com/forum/24/ihka...ten-45586.html

[tintrx]

I'll get back to you on when I decide to get on that project again. I had a fire in the engine compartment so the car is sitting right now.