My 1990 BMW E30 320i coupe automatic came with factory-fitted aircon which wasn't working. I asked my garage (9 months ago) to remove the compressor to save weight but have found that this has somehow disbled the heating system.
I know the matrix and valve are working well, the fan blows gallons of cold air and the cables and flaps work to deflect air about the cabin correctly.
Some of the wiring associated with the aircon was removed. I've recently re-attached the wires to the blue 'snowflake' aircon button and the amber 'recycle' button on the dash. They glow when pressed but have not cured the problem.
Still no hot air from the vents when the red/blue coloured temperature dial is turned to red and the fan is on! Just luke-warm air as if there is a flap (still) covering the heater matrix?
Does anyone know what's causing this? And more important, how to get some heat into the cabin before winter sets in!
Thanks
Richard
No heat after removal of aircon
Moderator: martauto
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Brianmoooore
- E30 Zone Team Member
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- Joined: Mon Jan 10, 2005 11:00 pm
The E30 aircon wiring is piggy backed onto the ordinary fan wiring, without disconnecting any of that wiring, so the operation of the fan shouldn't be affected by its removal.
The short answer to your problem is, the cause is whatever they left disconnected that they didn't need to touch while performing this act of vandalism on your car.
If the aircon switch and its plug is still there, remove the switch and check, with a 12 volt bulb, that there is power at the green/brown wire with the ignition on, and that there is power on the yellow wires with the ignition and fan on position 1, then again with the ignition on and the fan on position 4.
The short answer to your problem is, the cause is whatever they left disconnected that they didn't need to touch while performing this act of vandalism on your car.
If the aircon switch and its plug is still there, remove the switch and check, with a 12 volt bulb, that there is power at the green/brown wire with the ignition on, and that there is power on the yellow wires with the ignition and fan on position 1, then again with the ignition on and the fan on position 4.
Thanks for the swift repsonse.
I have just checked the wires. The 'snowflake' aircon and amber 'circulate' buttons are part of the same plug in my car. There is power to all three green/brown wires with the ignition on. There is also power to the two yellow wires with the ignition on and the fan on, in postions 1,2,3 & 4.
Does this help?
Can you tell me what I should do next?
Thanks
Richard
I have just checked the wires. The 'snowflake' aircon and amber 'circulate' buttons are part of the same plug in my car. There is power to all three green/brown wires with the ignition on. There is also power to the two yellow wires with the ignition on and the fan on, in postions 1,2,3 & 4.
Does this help?
Can you tell me what I should do next?
Thanks
Richard
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Brianmoooore
- E30 Zone Team Member
- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
As long as you checked with a bulb of at least a few watts, and not a meter, all that seems to be in order, and power should be getting to the fan motor.
There's no reason why they should have been in there to remove the aircon, but remove the access panel at the back of the engine bay, check that the fan blades can turn freely, and check that the blue and brown wires are connected to the motor.
If you still can't see what's wrong, remove the blue and brown wires from the motor, and connect them to the 12 volt bulb. Turning the ignition and fan switch on should light the bulb.
There's no reason why they should have been in there to remove the aircon, but remove the access panel at the back of the engine bay, check that the fan blades can turn freely, and check that the blue and brown wires are connected to the motor.
If you still can't see what's wrong, remove the blue and brown wires from the motor, and connect them to the 12 volt bulb. Turning the ignition and fan switch on should light the bulb.
I did test the wires with a bulb and power definitely gets to the fan. It blows at all 4 positions and the horizontal 'slider' controls divert the air up the windscreen, down the footwell and into my face - the trouble is, it's always cold air!
As hot water seems to be flowing through the matrix and the fan is working, I'm thinking that something leftover from the aircon (or an unconnected wire left by the garage that tried to remove it) means that a flap is covering the matrix? As if the car still 'thinks' it's in AC mode, so has blocked off the heater?
Does that make any sense?
Any thoughts on what I should try next?
Thanks for your help
Richard
As hot water seems to be flowing through the matrix and the fan is working, I'm thinking that something leftover from the aircon (or an unconnected wire left by the garage that tried to remove it) means that a flap is covering the matrix? As if the car still 'thinks' it's in AC mode, so has blocked off the heater?
Does that make any sense?
Any thoughts on what I should try next?
Thanks for your help
Richard
How exactly do you know that the valve is definitly working and hot water is flowing through the matrix?
Also i dont know whether any coolant pipes were disconnected when the compressor was removed but if so this could simply be an air lock?
Also i dont know whether any coolant pipes were disconnected when the compressor was removed but if so this could simply be an air lock?
Because the pipes going into and coming from the matrix are both hot!
I think that a flap is covering the matrix. It could be something leftover from the aircon (or an unconnected wire left by the garage that tried to remove it) meaning that the car still 'thinks' it's in AC mode, so is blocking off the heater?
I was hoping someone might have heard of this before I have to head into the deepest recesses of the dashboard to see what's going on.
Any ideas?
I think that a flap is covering the matrix. It could be something leftover from the aircon (or an unconnected wire left by the garage that tried to remove it) meaning that the car still 'thinks' it's in AC mode, so is blocking off the heater?
I was hoping someone might have heard of this before I have to head into the deepest recesses of the dashboard to see what's going on.
Any ideas?
Fair point but (to save time) I didn't mention that I've already been in and checked the valve and replaced the heater matrix. The heater matrix works perfectly and the fan works on all 4 positions it's just getting the hot air to the fan! As I said, I think that a flap is covering the matrix. Does anyone know if cars with A/C had an extra flap which covered the matrix (to stop any heat entering the vents) when the car was in AC mode?
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Brianmoooore
- E30 Zone Team Member
- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
Didn't read the OP carefully enough, and led you off in completely the wrong direction!
I have a couple of aircon heater boxes in stock, and when I get a spare half hour and am where they are, I'll have a look, and see if your theory is possible.
I have a couple of aircon heater boxes in stock, and when I get a spare half hour and am where they are, I'll have a look, and see if your theory is possible.
Hi Brian, no problem about the wrong direction!
I'd be very grateful if you could look at your aircon heater boxes just to see if there is a flap between the matrix and the fan. It would save me taking the whole lot out myself.
However, there has been a further development. My kind mechanic looked into it the other day and claims that the heater valve is working fine but the the presence of the remaining aircon parts is influencing the ECU. He thinks that, in effect, the ECU is telling the valve that the ambient temp is high, that the aircon is 'on' and that it must remain closed. So the hot water is not circulating through the matrix. By the way, he doesn't know if there definitely is (or is not) a flap between matrix and fan. He recommended I spoke to the reputable Alpinair to see if they might be able to plug a computer into the ECU and 'put it right'!
I've just spoken to Alpinair who were very helpful and insist that BMW intentionally made the aircon to fail in the heating mode. So that you'll always have heating (in a Bavarian winter for example) whatever state your aircon might be in. That makes sense to me. Given the matrix has been replaced, Alpinair suggested it must be either the valve or the red/blue dial which controls it. And from this site's Wiki section HEATING SYSTEM TROUBLESHOOT by Andrew Everett, which I've just re-read, it looks like it would have to be either the valve or the dial.
Does that make sense to you?
Thanks
Richard
I'd be very grateful if you could look at your aircon heater boxes just to see if there is a flap between the matrix and the fan. It would save me taking the whole lot out myself.
However, there has been a further development. My kind mechanic looked into it the other day and claims that the heater valve is working fine but the the presence of the remaining aircon parts is influencing the ECU. He thinks that, in effect, the ECU is telling the valve that the ambient temp is high, that the aircon is 'on' and that it must remain closed. So the hot water is not circulating through the matrix. By the way, he doesn't know if there definitely is (or is not) a flap between matrix and fan. He recommended I spoke to the reputable Alpinair to see if they might be able to plug a computer into the ECU and 'put it right'!
I've just spoken to Alpinair who were very helpful and insist that BMW intentionally made the aircon to fail in the heating mode. So that you'll always have heating (in a Bavarian winter for example) whatever state your aircon might be in. That makes sense to me. Given the matrix has been replaced, Alpinair suggested it must be either the valve or the red/blue dial which controls it. And from this site's Wiki section HEATING SYSTEM TROUBLESHOOT by Andrew Everett, which I've just re-read, it looks like it would have to be either the valve or the dial.
Does that make sense to you?
Thanks
Richard
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Brianmoooore
- E30 Zone Team Member
- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
Unless your car has the very rare climate control (temp. dial marked in degrees), the heater electric valve is only powered closed when the temp. dial is fully at or very nearly at the cold position. This ensures that when the heater is set to cold, there is absolutely no heat from the heater. No ECU has any control over that valve.
The passage you refer to in Everett's book is only applicable to a very small percentage of E30s, and is the one misleading blemish in an otherwise informative book.
As I've said, I haven't been able to look at a aircon/heater box yet, but I'm certain there's no electrically operated flap, as there's nothing in the wiring diagrams for one - just wiring for the recirculation flap motors. If there is a flap, it would have to be bowden cable operated.
P.S. Anyone had the heater hoses of under the bonnet? Does the hose that comes from the back of the cylinder head go to the bottom or top stub pipe on the bulkhead?
The passage you refer to in Everett's book is only applicable to a very small percentage of E30s, and is the one misleading blemish in an otherwise informative book.
As I've said, I haven't been able to look at a aircon/heater box yet, but I'm certain there's no electrically operated flap, as there's nothing in the wiring diagrams for one - just wiring for the recirculation flap motors. If there is a flap, it would have to be bowden cable operated.
P.S. Anyone had the heater hoses of under the bonnet? Does the hose that comes from the back of the cylinder head go to the bottom or top stub pipe on the bulkhead?
My heater switch or temp dial is the standard red/blue circular design.
Today I went back to check the state of play from first principles. I ran the engine up to working temperature (needle at 12 o'clock) and felt the hoses going through the bulkhead. To answer your P.S. above, it's the lower pipe that comes from the cylinder head that supplies the hot coolant to the matrix (via the valve) and the top pipe that takes it back to near the thrermostat, as far as I can see.
Both hoses were very hot which implies that water is flowing through the matrix. The valve may be broken but it must be open (I would think) if the top return hose is hot?
I then took the radio out and removed the panel with the heater controls and clock. I'd been assured that the temp dial was working (electrically) and the hot exit pipe would confirm that, but I'd always noticed that the dial was stiff to turn. On close inspection, the cable, attached to the lower edge of the dial, was not moving freely. The white plastic section was moving out of the cable casing when I turned it clockwise from cold to hot. When the dial was rotated clockwise the cable did not move as far as it looked it should! I applied a little WD40 and eased the cable back and forth. I tried to shift the white plasitc inner sleeve back into the cable housing. I then fully rotated the dial to max hot / clockwise / red to pull the cable to its maximum extent to, hopefully, open any flap to it's fulllest extent, and then re-fitted the panel.
Sadly, once theengine was back up to running temperature, there was only a slight increase in the temperature of the air coming out of the vents. Doh!
Does this not point to a flap over the matrix that's not opening properly? I don't know if the cable attached to the dial is attached to anything else at the other end(!) Do you? I've studied all the diagrams I can find but none seem to show a flap over the matrix? But surely that's the key?
Judging from your last pparagraph, I think we're agreed. So I'd be really grateful if you could look at one of your aircon/heater boxes and let me know what's on the end of the cable that's attached to the temp dial! Or if you could point me to a diagram of it anywhere?
My honest mechanic suggested (a couple of days ago) that I buy a replacement valve and temp dial off
Ebay and he replace both, but frankly I don't think that's the solution. As you say, "there's nothing in the wiring diagrams for one - just wiring for the recirculation flap motors" (which sound as if they're working fine btw), so surely it points to a mechanical, cable operated problem with the flap over the perfectly functioning matrix?
I'd be grateful for any help!
Thanks
Today I went back to check the state of play from first principles. I ran the engine up to working temperature (needle at 12 o'clock) and felt the hoses going through the bulkhead. To answer your P.S. above, it's the lower pipe that comes from the cylinder head that supplies the hot coolant to the matrix (via the valve) and the top pipe that takes it back to near the thrermostat, as far as I can see.
Both hoses were very hot which implies that water is flowing through the matrix. The valve may be broken but it must be open (I would think) if the top return hose is hot?
I then took the radio out and removed the panel with the heater controls and clock. I'd been assured that the temp dial was working (electrically) and the hot exit pipe would confirm that, but I'd always noticed that the dial was stiff to turn. On close inspection, the cable, attached to the lower edge of the dial, was not moving freely. The white plastic section was moving out of the cable casing when I turned it clockwise from cold to hot. When the dial was rotated clockwise the cable did not move as far as it looked it should! I applied a little WD40 and eased the cable back and forth. I tried to shift the white plasitc inner sleeve back into the cable housing. I then fully rotated the dial to max hot / clockwise / red to pull the cable to its maximum extent to, hopefully, open any flap to it's fulllest extent, and then re-fitted the panel.
Sadly, once theengine was back up to running temperature, there was only a slight increase in the temperature of the air coming out of the vents. Doh!
Does this not point to a flap over the matrix that's not opening properly? I don't know if the cable attached to the dial is attached to anything else at the other end(!) Do you? I've studied all the diagrams I can find but none seem to show a flap over the matrix? But surely that's the key?
Judging from your last pparagraph, I think we're agreed. So I'd be really grateful if you could look at one of your aircon/heater boxes and let me know what's on the end of the cable that's attached to the temp dial! Or if you could point me to a diagram of it anywhere?
My honest mechanic suggested (a couple of days ago) that I buy a replacement valve and temp dial off
Ebay and he replace both, but frankly I don't think that's the solution. As you say, "there's nothing in the wiring diagrams for one - just wiring for the recirculation flap motors" (which sound as if they're working fine btw), so surely it points to a mechanical, cable operated problem with the flap over the perfectly functioning matrix?
I'd be grateful for any help!
Thanks