Kleynie
A2OC Donor
Some may remember, a couple of years back, we had the seats in Adams A2 covered in leather/Alcantara, at the same time we had aftermarket carbon heated pads installed. Since then we have struggled to get the pads to work with the OEM heated seat rollers.
The back rest and the base of the seat had two separate heated pads, so we have two wires from the backrest and two from the base. What we had done wrong was wire these in series instead of in parallel, this effectively halved the voltage to each pad! Doh! The pads must be wired in parallel.
We knew that the original Audi pads use a thermistor to control the heat, these basically act as a sensor in each seat to sense the heat depending on the roller switch setting. We had an original loom pre-installed which presents 4 wires to each seat, two for the thermistor and two for the power to the heating pads.
We had a diagram that proved to be wrong, see attached, and this may have mislead us for a while, it stated that a 47K Ohm resistor should be installed in parallel with a 10K Ohm thermistor, whilst this worked, it only worked slightly on number 4 of the roller switches.
A bit of googling and many test runs on the bench and we finally nailed it. The thermistor circuit did not require a fixed resistor, it simply required a 6.8K Ohm thermistor as in the below link:
We soldered the thermistor to two lengths of wire, heat shrunk the exposed wires and inserted it into the seat base. It is wired as per the diagram, just not with the fixed 47K Ohm resistor. It now works a treat.
So for anyone doing a heated seat install, this has made it a whole lot easier, the carbon heating pads are very cheap, the hard bit will be getting the climate panel with the switch rollers - thanks to A2Steve for ours.
Please let us know if you have any questions if doing this install.
Ian & Adam.
This is the drivers seat:
The back rest and the base of the seat had two separate heated pads, so we have two wires from the backrest and two from the base. What we had done wrong was wire these in series instead of in parallel, this effectively halved the voltage to each pad! Doh! The pads must be wired in parallel.
We knew that the original Audi pads use a thermistor to control the heat, these basically act as a sensor in each seat to sense the heat depending on the roller switch setting. We had an original loom pre-installed which presents 4 wires to each seat, two for the thermistor and two for the power to the heating pads.
We had a diagram that proved to be wrong, see attached, and this may have mislead us for a while, it stated that a 47K Ohm resistor should be installed in parallel with a 10K Ohm thermistor, whilst this worked, it only worked slightly on number 4 of the roller switches.
A bit of googling and many test runs on the bench and we finally nailed it. The thermistor circuit did not require a fixed resistor, it simply required a 6.8K Ohm thermistor as in the below link:
We soldered the thermistor to two lengths of wire, heat shrunk the exposed wires and inserted it into the seat base. It is wired as per the diagram, just not with the fixed 47K Ohm resistor. It now works a treat.
So for anyone doing a heated seat install, this has made it a whole lot easier, the carbon heating pads are very cheap, the hard bit will be getting the climate panel with the switch rollers - thanks to A2Steve for ours.
Please let us know if you have any questions if doing this install.
Ian & Adam.
This is the drivers seat:
Attachments
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