Skoda Rapid Heater Re-circulation Motor Repair
In the autumn of 2018 the heater re-circulation motor (I'll refer to this as the HRM from now on) in my 2015 Skoda Rapid decided to fail. It had been making a grinding and clicking noise for a while and I had asked the local Skoda dealer to look into this during a routine service, which they didn't, but more on that later. The problem was that the motor failed in the re-circulate setting so the interior of the car steamed up very quickly and the windscreen couldn't be de-misted. Putting the air-conditioning on was a short-term solution up until the outside temperature dropped below 10 Celsius and that stopped working!
There isn't a lot of information online about the Rapid because it is a less common model than other Skodas, but it shares a lot of design with the Fabia and Octavia so it wasn't too hard to get diagrams showing where the motor was and how it works. To get at the HRM I had to remove the glove box (7 Torx screws) and the heater motor (5 Torx screws), total time about 10 minutes. I could then disconnect the HRM and remove it. As a stop gap, I jammed the 2 air flaps in the 'outside' position using folded bits of cardboard and that meant I could work on the HRM on the bench.
NOTE - Disconnect the battery before disconnecting the passenger airbag switch in the glove box. I didn't do this on an Audi A4 a couple of years ago and ended up with a persistent engine management fault. I am assuming that the Skoda is the same, so be warned.
With the motor on the bench it was obvious what had happened. It isn't a stepper motor, just a standard 12-volt one and the car electronics can drive it in either direction by changing the polarity. The end stop on these things is detected by a current sensing circuit, as the current drawn by the motor rises significantly when it is stalled. Normally power to the motor is cut when this happens. In the case of my motor, the case had sprung and a couple of the securing lugs had broken off resulting in the motor trying to run on beyond the end stops and eventually coming loose from the cogs connected to the air flaps.
I glued the housing back together using epoxy, but a bench test revealed that the motor had more torque than the glue could handle. After keying the ABS plastic with sandpaper and using a stronger epoxy it was a lot better, but in a moment of inspiration I realised that I could put 2 mini cable ties round it was well.
There isn't a lot of information online about the Rapid because it is a less common model than other Skodas, but it shares a lot of design with the Fabia and Octavia so it wasn't too hard to get diagrams showing where the motor was and how it works. To get at the HRM I had to remove the glove box (7 Torx screws) and the heater motor (5 Torx screws), total time about 10 minutes. I could then disconnect the HRM and remove it. As a stop gap, I jammed the 2 air flaps in the 'outside' position using folded bits of cardboard and that meant I could work on the HRM on the bench.
NOTE - Disconnect the battery before disconnecting the passenger airbag switch in the glove box. I didn't do this on an Audi A4 a couple of years ago and ended up with a persistent engine management fault. I am assuming that the Skoda is the same, so be warned.
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| Inside/outside air flaps behind the heater motor housing. |
With the motor on the bench it was obvious what had happened. It isn't a stepper motor, just a standard 12-volt one and the car electronics can drive it in either direction by changing the polarity. The end stop on these things is detected by a current sensing circuit, as the current drawn by the motor rises significantly when it is stalled. Normally power to the motor is cut when this happens. In the case of my motor, the case had sprung and a couple of the securing lugs had broken off resulting in the motor trying to run on beyond the end stops and eventually coming loose from the cogs connected to the air flaps.
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| Repaired heater re-circulation motor (VW/Skoda/Audi) |
I glued the housing back together using epoxy, but a bench test revealed that the motor had more torque than the glue could handle. After keying the ABS plastic with sandpaper and using a stronger epoxy it was a lot better, but in a moment of inspiration I realised that I could put 2 mini cable ties round it was well.
Fitting it back into the car was a bit of a pain, but it is working okay now. I want to adjust the range of travel and put a couple of extra screws in because Skoda seemed to have used the bare minimum to hold the main motor in place.
Speaking of whom... The Skoda dealer told me that to repair this would require the entire dashboard to be removed at an estimated cost of around £200 just to diagnose and they didn't do this because, well they never actually said why. Not surprisingly I have gone back to doing my own 5,000/10,000 mile schedule servicing and will use the local mechanics for anything I can't handle easily such as timing belts and suspension (might do the suspension if the weather is good!).
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