No Voltage to the heater valves. Where's the problem?

[Jehu]

I am reasonably sure the valves themselves are good and I just put in a new resistor. Where could the issue be? IHKA ? Heater Controls? The fuses under the hood all look OK. Is the other end of the Belden Cable from the Center Dash Vent Wheel switch accessible under the foot-well? I'm wondering if the other end of the cable came off the switch. I guess I can try an IHKA if I can find one used.. Maybe being right in the neighborhood of the welding at the gas pedal caused a problem there..

[632 Regal]

you have the heater on the highest setting right? Does the aux pump work? I hate electrical gremlins.

[Jehu]

No even with the center wheel set to full cold, dahs control dials to full cold and the AC ON its Hot,Hot ,Hot. I used one of those light bulb voltage testers on the water valve plug with the center dash vent wheel dialed full cold and there was no response ,no light so I concluded no voltage getting thru. If I am correct the wheel switch goes to the IHKA then to the harness out to the valves. Thankfully I don't have the sword , the IHKA final stage is about as easy as anything to replace,just plug in the new unit .. I just would rather target the right part... the only other parts in the system as far as I know are the dash controls and that switch at the other end of the dash tempt wheel cable..

[Paul in NZ]

No even with the center wheel set to full cold, dahs control dials to full cold and the AC ON its Hot,Hot ,Hot. I used one of those light bulb voltage testers on the water valve plug with the center dash vent wheel dialed full cold and there was no response ,no light so I concluded no voltage getting thru. If I am correct the wheel switch goes to the IHKA then to the harness out to the valves. Thankfully I don't have the sword , the IHKA final stage is about as easy as anything to replace,just plug in the new unit .. I just would rather target the right part... the only other parts in the system as far as I know are the dash controls and that switch at the other end of the dash tempt wheel cable..

have you got the ihka or ihkr?Either way with the drivers side temp set to full cold it should overdide what the ihk(x) is saying and turn on(or off) the voltage to the valves so that they close.

[Jehu]

have you got the ihka or ihkr?Either way with the drivers side temp set to full cold it should overdide what the ihk(x) is saying and turn on(or off) the voltage to the valves so that they close.

Whatever its called it is NOT the Sword.Its a black box. I thought both the temp wheel(between the center dash vents) and the dual controls each went thru the IHK? before leading to th Water Valves. Anyway I am boggled. Everything worked fine before the welding, then after it all wasn't working. I guess I'll just have to try first with the IHK? and if that doesn't fix it what next?

[Paul in NZ]

Whatever its called it is NOT the Sword.Its a black box. I thought both the temp wheel(between the center dash vents) and the dual controls each went thru the IHK? before leading to th Water Valves. Anyway I am boggled. Everything worked fine before the welding, then after it all wasn't working. I guess I'll just have to try first with the IHK? and if that doesn't fix it what next?

no just the dual wheels controls the temp,and only the drivers side overides the control unit.You feel/hear a slight click at each end (ie full hot or full cold)I guess you could try applying 12v directly to the heater valves( i am not sure which wires) to see if they then close.

[Jehu]

On my model the center wheel most definitely controls the water valves ;Open=Heat,Closed=Cold or some mix set in between by a plusing of volatge. That I get no change from Hot when dialing it to where it should close the valves and I see no indication of volatge at the pins on the plug under the hood at the valves suggests the the signal from the switch isn't being passed from the IHKA to the valves if I am understanding the pathway correctly. Weather the dials on the control unit with the vent sliders also operates the heater/water valves or operates stepper motors to allow mixing I'm uncertain.. Seems to me though since wherever the dials are and or the wheel i get nothing but hot and the valves should be good(opened and inspected,all clean) either the switch is not being moved by the wheel cable to signal the valves to close or the signal is not being routed from whereever it goes after the switch onto the valves.. since I believe the signal goes from the wheel switch to the IHKA I surmise the IHKA has failed possibly due to some unanticipated effect during welding and so I think I'll grab this

[Paul in NZ]

On my model the center wheel most definitely controls the water valves ;Open=Heat,Closed=Cold or some mix set in between by a plusing of volatge. That I get no change from Hot when dialing it to where it should close the valves and I see no indication of volatge at the pins on the plug under the hood at the valves suggests the the signal from the switch isn't being passed from the IHKA to the valves if I am understanding the pathway correctly. Weather the dials on the control unit with the vent sliders also operates the heater/water valves or operates stepper motors to allow mixing I'm uncertain.. Seems to me though since wherever the dials are and or the wheel i get nothing but hot and the valves should be good(opened and inspected,all clean) either the switch is not being moved by the wheel cable to signal the valves to close or the signal is not being routed from whereever it goes after the switch onto the valves.. since I believe the signal goes from the wheel switch to the IHKA I surmise the IHKA has failed possibly due to some unanticipated effect during welding and so I think I'll grab this

i am pretty sure the IHKA unit is the unit for cars with the three small horizontal wheels and the buttons rather than the three big wheels and sliders...I am also pretty sure the wheel between the vents only controls a stepper motor to direct heated air towards or away from those central dash vents.

[Jehu]

i am pretty sure the IHKA unit is the unit for cars with the three small horizontal wheels and the buttons rather than the three big wheels and sliders...I am also pretty sure the wheel between the vents only controls a stepper motor to direct heated air towards or away from those central dash vents.

Not to sound argumentative but I have seen the unit in my model when changing the Cabin Micro Filter and it is what is pictured in the ebay auction i linked above. Weather its correct nomenclature is IHKA I'll leave for BMW to say if there is another control unit beside this and the sword which looks like this maybe that's it.

[Paul in NZ]

Not to sound argumentative but I have seen the unit in my model when changing the Cabin Micro Filter and it is what is pictured in the ebay auction i linked above. Weather its correct nomenclature is IHKA I'll leave for BMW to say if there is another control unit beside this and the sword which looks like this maybe that's it.

no problems mate...whatever... GOOD LUCK WITH IT