Late Mode Recirculation Issues

[HJ1981]

I have been digging around for a few days now, this is for a late model (1990) E30 with factory aircon.

The recirculation/fresh air flaps are attached via two motors (one on each flap) and since they day i got the car, they never operated.

I did replace the AC switch (snowflake for AC and Recirc), i also followed the manual till i hit a block.

Basically, the blower speed is activated when the recirc button is depressed, but flaps stay open.

I verified that the switch is receiving power, but the motors are not receiving power.

The manual shows the location of two relays (one for each motor) behind the panel, which i removed. Surprisingly there are no relays in my car, the yellow and white wires (that should go between the motors and the relay) disappear in the main harness behind the HVAC. There are no signs (as of now) that anything has been cut, removed, broken etc and i could not find any evidence that BMW changed the relay location or has another setup.

I shall be removing the dash trim under the steering wheel to investigate the C204 harness (which feeds to the HVAC and Radio harness). But i doubt BMW moved the relays anywhere else, either someone "cut" those relays and their harness completely off, or BMW did something in 1990 that they did not mention?

Has anyone come across anything similar?

[Brianmoooore]

http://www.autolib.diakom.ru/CAR/BMW/19 ... /fig05.pdf Is this the circuit diagram you are following?

[HJ1981]

http://www.autolib.diakom.ru/CAR/BMW/19 ... /fig05.pdf Is this the circuit diagram you are following?

No i am following this on Page Blow Controls Troubleshooting but schematic looks the same :

http://shark.armchair.mb.ca/~dave/BMW/e30/e30_89.pdf

Regardless, on both diagrams it shows the "Recirculation Motor Relay", which i should see two of but i can not find them behind the HVAC control panel (which was a bit of a pain to remove).

Various HVAC diagrams show the relays to be directly behind the HVAC panel, i removed everything there as well as the center console and...nothing, no relays or even the "hot water cut off switch" that should be close by.

This is a random image i found online, which shows how both relays just sit behind the panel (the two silver caps):



Either one of the previous owners cut that whole harness, wires, relays and sockets off completely or BMW did something and moved them to another location.

[Brianmoooore]

My link is a MUCH easier diagram to follow than the official BMW one in your link.
I've never really studied it in detail before, since E30's with aircon are rare in the UK, and those that I've dealt with haven't had electrical problems with the flap motors, but if this wiring diagram is correct, there's an error in the labeling. It's not one relay for the LH flap and one for the RH flap, but one to power them both open and the other to power them both shut.
Unless the flap motors were changed to spring loaded return versions, it's difficult to see how they can work without relays, so, if you follow the yellow and white wires from the motors, you must come to the relays.

[Brianmoooore]

Just had to go to the workshop, and while there I had a look at a '93 touring, which has its dash removed. It has two silver relays, exactly as shown in your pic.

[HJ1981]

Just had to go to the workshop, and while there I had a look at a '93 touring, which has its dash removed. It has two silver relays, exactly as shown in your pic.

I am getting the feeling, someone was in there and gutted the relays and their respective harness off and tucked away the cut wires in the factory cable wrapping.......

I shall still trace that whole harness and take a closer look at it for any signs of cuts.....But yes, those relays should be directly behind the control panel.

Do me a favour please, since your dash is off. Trace that harness, where the relays attach to, they should lead back to C204, under the steering column to the right side (maybe in your case left side being a RHD car). Just verify this is correct with me?

[Brianmoooore]

C204 on my car is located just above the motor part of the electric heater valve.
All the wiring associated with the aircon switch, flap motors and relays is located within the small area in front of the relays, with the loom to the C204 leading off to the left, then going through a gap in the heater housing, right under the LH flap, before emerging behind the heater box and going to the C204.
The only part of this sub loom that isn't readily visible, is the pprox. 125mm of loom that goes through the box.

[HJ1981]

After spending 2-3 hours checking every wire in that harness, i found the problem (s).

They say a picture is worth a thousand words:



Looks like someone fused both yellow wires directly from the switch, as well as the violet/black wire.

Since the relays are completely missing, i would say 95% chance someone got in there and also cut them completely off.

I probably will remove the entire harness and carefully separate every wire and fix it correctly.

[Brianmoooore]

I'd love to know why!!!
If you're not to worried about it being absolutely OE, a couple of these would do for the repair: https://cpc.farnell.com/multicomp-pro/m ... elay%2012v , soldering wires directly to the relay pins and covering them with a bit of heat shrink.
Before you go too far, I'd check that the flap motors both work properly. Power them up with 12 volts, connected + to yellow and then + to white. Connected one way they should open, and the other way they should close. They are designed to be powered continuously without damaging them.

[HJ1981]

I'd love to know why!!!
If you're not to worried about it being absolutely OE, a couple of these would do for the repair: https://cpc.farnell.com/multicomp-pro/m ... elay%2012v , soldering wires directly to the relay pins and covering them with a bit of heat shrink.
Before you go too far, I'd check that the flap motors both work properly. Power them up with 12 volts, connected + to yellow and then + to white. Connected one way they should open, and the other way they should close. They are designed to be powered continuously without damaging them.

So, first came the radio harness, which i had to rebuild to OE.

Secondly came the door harness, where the regulator was pressing on the loom.

Now i find this.....

Yes, i do plan on juicing the motors directly, but i also found out something. I cut the wires at the switch and connected them separately, this caused the blower to activate when the recirc is pressed, but doing so made speed 1 on the blower not activate without the recirc. If i let both wires touch, as i found them, then the blower works on speed 1 without recirc. Which tells me that the blower resistors are bad (or there is another cut wires somewhere) and someone went for a cheap cut and join the wires instead of replacing the resistors.

The black/violet wire from the switch also has a cut, but it is deep inside and i would need to remove the radio and possibly the control panel again to get proper access to test. But so far, as of now, someone surely "bypassed" the speed 1 blower settings.

The saga continues.....

[HJ1981]

Good news, both motors work when juiced, thankfully.

I repaired the yellow wires from the switch, but then i found this:



As if fusing two wires was not enough, someone fused all 4 black/violet wires. I remedied this and everything works except the motor flaps and the 1st speed fan with recirculation off.

A new blower resistor should help here, according to the schematics. But the relays are still a mystery, should i go ahead and remove the whole harness?

Note: One of those wires is for the evaporator temperature sensor, which sends a signal to the compressor (on/off) in combination with the high/low pressure switch to control the compressor and detect ice, no wonder my compressor was acting up despite full refrigerant. Imagine spending €150 on a new evap sensor only to have made no difference, due to someone wiring that mess.

Brian, is your dash still out? can you find a part number for that HVAC harness? i can not find it anywhere.

[HJ1981]

Sadly....someone cut the relays completely off, broke their mounting spot and just spliced everything in:



I can probably rebuild this, BMW still sell relay sockets and the pins and the two relays i require, checked locally for a total of €50 or so and do the wiring myself.....harness would need to come off to solder everything correctly. Or i get lucky and find a harness with those relay sockets and just swap them over, but so far i can not find any used ones on ebay Germany or UK that match.

Or get two of those relays you linked above, and just straight solder the correct wires to them and call it a day. The shit someone did to that harness, just pisses me off.....

[Brianmoooore]

Haven't been to the workshop today to look, but I doubt that any label on it would have BMW's part number on it. More likely a production code from the subcontractor that made it.
That loom is an easy repair for less than a fiver.
Do you have the complete dash off of the car? Things would be a lot easier to work on with it out the way, and you'll be able to see any other bodge ups.
Dash comes off easily - instrument cluster out, release heater controls, glove box panel off, under dash panel off, unplug dash upper loom, remove components connected to lower loom and unplug them, two bolts each side, an lift off.
Helps with putting it back if the A pillar trims are off, so they my as well come off at the start, and although I've never removed a dash with the centre consoles in place, I can't think offhand of any reason why they can't stay.
The only problem you sometimes come across is if someone has been threading wires behind the dash, and woven them around the dash upper loom which stays on the dash.

[HJ1981]

Haven't been to the workshop today to look, but I doubt that any label on it would have BMW's part number on it. More likely a production code from the subcontractor that made it.
That loom is an easy repair for less than a fiver.
Do you have the complete dash off of the car? Things would be a lot easier to work on with it out the way, and you'll be able to see any other bodge ups.
Dash comes off easily - instrument cluster out, release heater controls, glove box panel off, under dash panel off, unplug dash upper loom, remove components connected to lower loom and unplug them, two bolts each side, an lift off.
Helps with putting it back if the A pillar trims are off, so they my as well come off at the start, and although I've never removed a dash with the centre consoles in place, I can't think offhand of any reason why they can't stay.
The only problem you sometimes come across is if someone has been threading wires behind the dash, and woven them around the dash upper loom which stays on the dash.

The middle console is off, so is the trim behind the glove box, the trim on the side and under the cluster/gauges. Thing is i am working on the car as it is parked outside in the parking lot so i can not just leave things on the ground.

But yes, it is at least, straight forward to repair that with a couple of relays installed. Just pisses me off, someone went through all that trouble to bypass the relays, it is still a lot of work to save some money.

[Brianmoooore]

Just pisses me off, someone went through all that trouble to bypass the relays, it is still a lot of work to save some money.

But they didn't achieve anything. The relays are essential to reverse the motors, so without them, the motors will either completely shut or open the flaps, where they will remain for evermore.
Sounds like you're only four bolts and a plug from removing the dash. Engine will start and run as normal without the dash or cluster in place, apart from the battery won't charge properly.

[Theo]

Interesting that your loom has the plug for the automatic heater control (climate control), is that normal Brian?

[HJ1981]

Just pisses me off, someone went through all that trouble to bypass the relays, it is still a lot of work to save some money.

But they didn't achieve anything. The relays are essential to reverse the motors, so without them, the motors will either completely shut or open the flaps, where they will remain for evermore.
Sounds like you're only four bolts and a plug from removing the dash. Engine will start and run as normal without the dash or cluster in place, apart from the battery won't charge properly.

Exactly, and i found yet another splice near the S204 plug under the dash....freaking can of worms whoever worked on this.

I would require removing the ABS, DME, Glovebox and Clusters to remove the dash....very tempted right now, since that last harness that sneaked tightly at the blower housing for the resistors and the blow motor power are impossible to reach at the moment. Oh and the steering wheel needs to come off lol, forgot that big round thing XD

I may need to cut that small harness (for the resistors and blower motor) to get the bigger harness off, then splice them.....that is the shortcut instead of removing the dash. Thing is, i just do not have a place to lay the dash once removed....or try booking at the DIY on Monday and do it there (and pay for space too).

[HJ1981]

Interesting that your loom has the plug for the automatic heater control (climate control), is that normal Brian?

Thise model has some very nice options, that i could not find on other models after 8 months of searching. AC, Auto heat, locking diff, sport seats, sport wheel, illuminated shift knob, sunroof, M suspension, central locking, power windows....list goes on. It is also a Swiss model called "Führer Edition" which also comes with M-tec 2 rear spoiler and other goodies.

[Brianmoooore]

Interesting that your loom has the plug for the automatic heater control (climate control), is that normal Brian?

Thise model has some very nice options, that i could not find on other models after 8 months of searching. AC, Auto heat, locking diff, sport seats, sport wheel, illuminated shift knob, sunroof, M suspension, central locking, power windows....list goes on. It is also a Swiss model called "Führer Edition" which also comes with M-tec 2 rear spoiler and other goodies.

Sounds like the local equivalent of the UK 'Sport' - a 'special edition' with assorted pre ticked option boxes.
I'm not surprised that part of the climate control loom is included in the aircon loom, in the same way as part of the aircon loom is included in the heater feed loom in non aircon cars. A few bits of unused wire are a lot cheaper than running more production lines and dual stocking.
Fairly sure I've removed E30 dashboards without removing the steering wheel. It's still on the one I've been looking at, complete with centre cap, so I don't think it's been touched.

[Brianmoooore]

If the heater fan will work on all speed settings with the aircon switched off, there is nothing wrong with the resistor pack.

[HJ1981]

If the heater fan will work on all speed settings with the aircon switched off, there is nothing wrong with the resistor pack.

Speed 1 is non functional with the aircon switched off.

I picked up a soldering torch and some solder paste, started soldering strong connections on areas i am sure of, such as the AC and Recirculation switch.

Started to visualize in my head how i would make new connections from the harness, to the relays, to the motors, looping around and back etc.

Relays should arrive tomorrow, then i can twist connections to quickly test everything before a final solder.

[HJ1981]

After spending numerous hours studying three electrical plans (one for the blower, one for the recirculation and one general overview), the changes made are the following:

S250 Splice: This comes after the S240 connector, splits into several connections for various wires of different thicknesses (from 0.5mm to 2.5mm) to the blower switch, AC switch, Recirculation Switch as well as to the relays for the flap motors.

The two 0.5mm Green/Brown wires, that come out of S250 and directly goes to power the relays are there, just cut (one for left relay, one for right relay).
The entire relay area is cut, which means no relays, no Brown ground, no bridge, nothing.

The Yellow and White wires for the motors are there, bridged together and connect to the blue connector for temperature control (they are connected to nothing, just spliced in to make it look factory).

The two 1.5mm Green/Brown wires coming out of the AC/Recirculation switch are cut at the S250 splice, but still present at the switch itself. They splice with S250 as well as the 2.5mm Green/Brown that feeds to the blower speed control.

The two 2.5mm Yellow wires from the AC/Recirculation switch are cut at the S250 splice, but still on the switch. They splice as S251, which powers speed 1 switch blower speed as well as the resistors (hence why one pressed recirculation switch, the low speed blower kicks in).

The Black/Violet wires splice at S261 which connect the AC switch, Evaporator Temperature Control and C136 connector. Which then continues to the Aux Fans. The two 0.5mm wires have been cut.

Long story short, some of the S250, S251 and S261 splices have been "moved" to directly behind the heater panel. The good news is that according to the diagram(s), one can splice things back together, will not be pretty but everything should work. Need to build new ground(s), relays, bridges and connect the whole S250 0.5mm Green/brown again.

I shall start soldering all those and "prepare" the relay wiring.....It seems whoever was in there actually followed the diagram indeed in order to butcher the relay + related wiring....I had to undo all of this to see what i have to work with first before this headache.....

[HJ1981]

Well, it seems i keep finding surprises with this car.

As i replaced the blower resistors, i saw the recirculation flaps. The driver's side works fine and pushes against the motor, the passenger side does not. It would seem something is broken, be it where the rod meets the flap, or the plastic mechanism, it is impossible to determine with the HVAC unit installed in the car.

It looks like, if i wish to fix this correctly, the dash needs to come off as well as the HVAC box and put it on a work table and start repairs (if i could).

Since i ordered new colour and thickness correct wires, as well as new Tesa wiring loom tape, i loosely re-installed everything till everything arrives. There is no R134a in the system, since i drained it to fix a leaky expansion valve o-ring.

Would be nice to reseal the heater valve "while you are in there" as well, also get new gaskets from BMW which require 10 day order.....

So for now....everything is on hold till at least my currently ordered parts arrive. I need your advice Brian, think i should go ahead and order parts, then when they arrive take off the dash and HVAC to do this correctly?

[Brianmoooore]

Do you have the complete dash off of the car? Things would be a lot easier to work on with it out the way, and you'll be able to see any other bodge ups.
Dash comes off easily - instrument cluster out, release heater controls, glove box panel off, under dash panel off, unplug dash upper loom, remove components connected to lower loom and unplug them, two bolts each side, an lift off.
Helps with putting it back if the A pillar trims are off, so they my as well come off at the start, and although I've never removed a dash with the centre consoles in place, I can't think offhand of any reason why they can't stay.
The only problem you sometimes come across is if someone has been threading wires behind the dash, and woven them around the dash upper loom which stays on the dash.

[HJ1981]

Do you have the complete dash off of the car? Things would be a lot easier to work on with it out the way, and you'll be able to see any other bodge ups.
Dash comes off easily - instrument cluster out, release heater controls, glove box panel off, under dash panel off, unplug dash upper loom, remove components connected to lower loom and unplug them, two bolts each side, an lift off.
Helps with putting it back if the A pillar trims are off, so they my as well come off at the start, and although I've never removed a dash with the centre consoles in place, I can't think offhand of any reason why they can't stay.
The only problem you sometimes come across is if someone has been threading wires behind the dash, and woven them around the dash upper loom which stays on the dash.

Corect again, but this time the HVAC will come off, since there is no freon/R134a in the system, one can pinch the heater hoses in the engine bay.

I shall start looking and ordering new HVAC and heater pipe gaskets and o-rings tomorrow......

[HJ1981]

I finally received all the gaskets, o-rings, wires etc related to do a full repair.

I got the dash out, was pretty straight forward, just lots of small screws holding trim pieces. The entire heater box was removed, since the late model boxes have the resistors up at the blower, that plug is sandwiched inside and to remove it, the box needs to be split in half. Since i already had a small leak at the expansion valve and an empty system, might as well, just 4 nuts and a support and it just snugged off.

After a headache of following diagrams, fixing various connections and what not, the motors still did not work, despite all new wires and relays.

I then found a russian site that has the exact same AC/Heater system from an E30 325iX. Apparently there are NO relays for vehicles equipped with automatic heater control AND air conditioning combined. It is all handled directly by the temperature control motor (when you adjust the cabin temperature). The motors are wired in such a way, that it connects directly to the blue plug, as well as the Green No.4 wire from the recirculation switch.

I quickly searched for a new price from BMW.....€610 was the cheapest offer i found for that motor and it is under order only. So i removed mine, it is held together with 4 clips, will open it up and give it a clean and look for any broken, burned or failed internal pieces.

Incase anyone is wondering the BMW part number is : 64111386821

The sticker on the part is :



On top of that, the blower cover housing contains two pins, one for each side of the recirculation flaps. The passenger side was completely broken, apparently another "common" issue with the flaps.

Part number: 64111372507

Price new from BMW (if they have stock, it is NLA/In production: €239 (over GBP 300 for you UK guys).

I used plastic safe epoxy and it is holding, but it is only a matter of time before that will break eventually.

Car is in the shop, i chased all other harnesses and cables, clearly someone was messing around with the HVAC harness, but the second dash harness (that feeds the cluster, lights, central locking etc) are all factory and no evidence of tampering.

If i can not fix the TCU (temperature control unit) then i shall close the flaps and leave it at that, i do plan on keeping the car as long as possible and do have everything working, but €600+ for that is crazy and i searched virtually all used parts online (Europe, US, NZ, AUS etc) and so far none have shown up. Regarding the top housing, still €240 for a plastic cover that would crack and break in 20 years is also hard to swallow.

Here is a Russian site (have your' browser translate it) that shows the common problem with the housing : https://www.drive2.ru/l/481053105778065823/

It was not a waste of time, the HVAC gasket in the interior is gone and possibly the source of squeaks, i got to remove the evaporator and see 30 years of dirt on it (to be cleaned) and found out more interesting wiring info on my specific E30. Will be updating this as i continue.

[DanThe]

Your pictures of the fused wires with cloth wrap look like factory connections to me

[HJ1981]

Your pictures of the fused wires with cloth wrap look like factory connections to me

Maybe, saw more of those "sloppy" wrap around various places as well.

[Brianmoooore]

Your pictures of the fused wires with cloth wrap look like factory connections to me

Maybe, saw more of those "sloppy" wrap around various places as well.

The black/purples? Definitely a factory join.

[HJ1981]

Your pictures of the fused wires with cloth wrap look like factory connections to me

Maybe, saw more of those "sloppy" wrap around various places as well.

The black/purples? Definitely a factory join.

Just black, more like duck tape than electrical tape as shown in my previously above pictures.

[Brianmoooore]

Which pic. is this? There aren't many plain black wires in an E30.

[HJ1981]

Which pic. is this? There aren't many plain black wires in an E30.

Post No.8 where it shows the black cloth over the yellow wires.

I am uncertain what to do at this point, cough up the €600 for a new temperature controller from BMW, or probably hunt down a hard to find complete heater/air conditioning box that comes with the front controls, harness, evaporator, heater etc and swap it out, both would run more/less the same including the labour to remove everything again.

There is also no guarantee, that the €600+ control unit would repair the issue, though after testing it is responsible for everything for this specced out climate control option.

[HJ1981]

I did some more digging into this matter, and found several German threads regarding people installing AC system in their E30s that came without aircon from the factory.

A "popular" option is going for the "automatic heater and climate control" system, which is what my E30 was equipped with from the factory. These threads go back as far as 2003 to 2011, regarding if one should get a "normal" system or the "automatic" system. I found some very useful info there, regarding the automatic system.

There are built in relay "blocks" in the circuit board, which over time, like any other relay would burn out or get loose over the years. Back then BMW was offering the new control units (for vehicles fitted with auto heat only as well as auto heat and climate control) for €400, used ones were running in the €100 to €200 range. Today, as i mentioned in my previous posts, they cost new €600.

One gentleman actually purchased several used ones, and found the cause, the burned out relays. They get burned out, since they are constantly "charged" and sending a signal to both recirculation flap motors, only when the recirculation button on the switch is depressed, does the control unit reverse polarity, causing the flaps to open. Here is his analysis for this control unit (i used google translate from German to english):

"What is often the case with a defective relay is that when the switch is pressed, the relay picks up and these (work) contacts are still OK. Then the flaps close.

If you then release the air recirculation switch again, the relay switches off again, but the normally closed contacts are worn out or burned due to the long years of pressure and no longer switch through.

Then the flaps remain in the "circulating air" position.

I already had the problem with my M3 at the time and measured it all because I didn't know the control unit at that time and as a first solution then applied voltage in the "open flap" direction until the flaps were open and then later exchanged the relay."

So, one could theoretically open up the control unit and desolder the relays and solder in new ones, if one could find parts online. Sometimes the solder becomes loose (similar to replacing the SI batteries or that flickering brap pad light due to the resistor). It is pretty interesting, i found maybe 30+ threads regarding people wanting to install this system, or convert to it (do not ask me why) but it appears that it is common for those integrated relays to get burned out eventually. Solution would be to attempt to repair the circuit board relays, or get a new control unit.