Heater stepper motor problems
Discussion
I am currently servicing the heating and ventilation on the Tamora and have it all in bits. Seeing is beliving 
Incredible design and quality of parts!!!
Anyways having stripped out the covers and flaps etc I have a feeling either the motor or the gearbox is knackered on the stepper motor. Unfortunately availability is zero new or £100 second hand, yep £100! Before I go second hand I want to try and check if the motor and or gearbox are bust.
Any tips on testing? If I split the motor and gearbox both rotate freeley, however if I put power to the motor it starts rotating then after 10/15 seconds it stops. Anyone know how this motor unit should work? What does the accuator actually do - does it simply cut the supply when the flap is fully open?
Any tips guidance or pointers gratefully received, as would be a decent second hand solution if anyone has got one!
Incredible design and quality of parts!!!Anyways having stripped out the covers and flaps etc I have a feeling either the motor or the gearbox is knackered on the stepper motor. Unfortunately availability is zero new or £100 second hand, yep £100! Before I go second hand I want to try and check if the motor and or gearbox are bust.
Any tips on testing? If I split the motor and gearbox both rotate freeley, however if I put power to the motor it starts rotating then after 10/15 seconds it stops. Anyone know how this motor unit should work? What does the accuator actually do - does it simply cut the supply when the flap is fully open?
Any tips guidance or pointers gratefully received, as would be a decent second hand solution if anyone has got one!
Thanks very much for the response. I think it’s different on the Griff but sounds like the same principle. Gearbox and motor separated. Both appear to turn ok by hand.
If I connect the motor without the gearbox should it continue spinning until I disconnect power as the actuator is not connected to tell it that it’s reached the end of its cycle?
If I connect the motor without the gearbox should it continue spinning until I disconnect power as the actuator is not connected to tell it that it’s reached the end of its cycle?
Thank you - the design is just laughable with possibly the worst heater flap arrangement imaginable!
So can I just check I have this right. At ignition the motor immediately rewinds all the way back to flap zero regardless of setting ie the flap comes down until it hits the buffers.After a short time the motor will then lift the flap until it either hits the setting on the heater controller or the acuator arm depresses the microswitch at fully open. Is this correct?
Reason I need to check this is I have seperated the gearbox and motor and need to reassemble them on there right settings before I start fannying around with the POD settings for flap zero and checking everything works as it should.Obviously assuming the motor/gearbox arent f
ked!
So can I just check I have this right. At ignition the motor immediately rewinds all the way back to flap zero regardless of setting ie the flap comes down until it hits the buffers.After a short time the motor will then lift the flap until it either hits the setting on the heater controller or the acuator arm depresses the microswitch at fully open. Is this correct?
Reason I need to check this is I have seperated the gearbox and motor and need to reassemble them on there right settings before I start fannying around with the POD settings for flap zero and checking everything works as it should.Obviously assuming the motor/gearbox arent f
ked!Well what a faf but we have a result! The motor has 6 cables with another two going to an actuator. As Dave said when you power up the motor automatically turns searching for its flap closed, cold position. On mine there is an acuator that triggers a micro switch when the flap is fully closed which stops the motor turning and shredding gearbox teeth.
The motor will not reopen the flap to your desired setting unless the micro switch has been triggered so its essential that the flap triggers the microswitch at its fully closed position. Some neoprene gaskets later and sealing all joins I have a full blast of cold air via the lower dash vents and hot air via the upper dash and drivers footwell vents. The flap moves freely to all the desired positions. No new motor required thankfully.
Time consuming but very simple when you know how it all works. Absolute shocking quality by TVR but quite clever in its simplicity. Thank you all for your help!
One last question - I have not changed anything on the POD settings for flap zero as I dont need to. The flap is closing and opening as it should do. But was does adjsusting flap zero actually do? The micro switch tells the motor the flap is fully closed and it stops so what effect does changing flap zero have on the settings? Asking out of curiosity really
The motor will not reopen the flap to your desired setting unless the micro switch has been triggered so its essential that the flap triggers the microswitch at its fully closed position. Some neoprene gaskets later and sealing all joins I have a full blast of cold air via the lower dash vents and hot air via the upper dash and drivers footwell vents. The flap moves freely to all the desired positions. No new motor required thankfully.
Time consuming but very simple when you know how it all works. Absolute shocking quality by TVR but quite clever in its simplicity. Thank you all for your help!
One last question - I have not changed anything on the POD settings for flap zero as I dont need to. The flap is closing and opening as it should do. But was does adjsusting flap zero actually do? The micro switch tells the motor the flap is fully closed and it stops so what effect does changing flap zero have on the settings? Asking out of curiosity really
Finally we have a result! Changing point zero does fine tune it but be warned get it wrong and you run the risk of shredding plastic teeth in the gearbox or burning the motor.
On mine, and I suspect they are all different on all cars, you can bend the actuator arm to adjust the micro switch kicking in at closed in the cold position. By increasing the flap zero number it fine tunes the flap and pulls it in tighter to fully closed. However the higher you go with the number the extra strain on the motor as it pulls the flap tighter against the sealing lip. This also means it reduces the flap height at full hot and may not give a good seal on fully hot.
Conversely set the flap zero number to low and the flap doesn’t reach the seal on full cold and goes to far on full hot again straining the motor and gears.
I wouldn’t be fiddling with flap zero in the pod settings without taking the cover off the heater flap and seeing what is happening as there are many variables and there are currently supply problems with new motors.
The main cause of my problems apart from it not being set up right was that someone had tried to fix it, failed, and just completely blocked off the cold vent, therefore hot air only! Furthermore the arm mechanism was fouling on the motor bracket preventing the flap from closing. I would not have been able to sort any of that just by playing with flap zero.
Wish I was on an hourly rate!
On mine, and I suspect they are all different on all cars, you can bend the actuator arm to adjust the micro switch kicking in at closed in the cold position. By increasing the flap zero number it fine tunes the flap and pulls it in tighter to fully closed. However the higher you go with the number the extra strain on the motor as it pulls the flap tighter against the sealing lip. This also means it reduces the flap height at full hot and may not give a good seal on fully hot.
Conversely set the flap zero number to low and the flap doesn’t reach the seal on full cold and goes to far on full hot again straining the motor and gears.
I wouldn’t be fiddling with flap zero in the pod settings without taking the cover off the heater flap and seeing what is happening as there are many variables and there are currently supply problems with new motors.
The main cause of my problems apart from it not being set up right was that someone had tried to fix it, failed, and just completely blocked off the cold vent, therefore hot air only! Furthermore the arm mechanism was fouling on the motor bracket preventing the flap from closing. I would not have been able to sort any of that just by playing with flap zero.
Wish I was on an hourly rate!
mines ended up on 10 but it is sealing against some neoprene tape at fully open and fully closed. Not sure I qualify as the right hands though, as you will see from this thread I rely on the advice of others.? Long live pistonheads 
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