Add seat heaters to 987 era porsche

To add seat heaters to 987 era model Porsches, you can add aftermarket seat heaters which bypass all the controls in the car and connect directly to an ignition or battery connection or install factory heating elements, add wiring, reprogram controls and then have factory style seat heaters. This is what I did for my 2008 Cayman S . The Cayman has a controller in the center dash area which transmits digital signals to another module that supplies the power to the seat heaters. In the Cayman the module is located above the relay carrier in the upper left section of driver footwell. For the Cayman you will need to buy a complete climate control module from Porsche (~$500) or used one from ebay ($80). I bought used. The used one had disfigured temp and fan sliders, but I exchanged the sliders with the ones from my car unit. You need to remove seats from car, undoing any electrical connectors. Pull out the black piece on the yellow connector and the connector separates. Cover the sill with thick blanket, rotate seat and remove. You need to partially remove the leather seat covers to place the factory seat heating elements on the seat foam pieces. Here are pics of the Cayman heating elements and what the seats look like with covers somewhat removed.

Remove the adhesive cover material and apply to foam cushions.

Same for back cushion.

Connect seat heating elements to each other and route leads under seat. Recover and reassemble seats. Route the bare metal terminals up near the yellow connector housing.

Take apart the yellow connector housing. It has three receptacles inside the housing that make connections: two grey and one black. You will be installing the male spade terminals from the seat heaters into the black receptacle.

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Install the red terminal from seat heaters in location 8 of black receptacle and the brown into location 13. Reinsert black receptacle into yellow housing

Reassemble yellow female connector housing and install in place.

Next is the addition of wires to the yellow male mating connector to the yellow seat housing.

Disassemble the male mating connector housing .

Run a ground wire (black in picture) from chassis ground under seat to pin 13 and you will need the special connector shown. P/N BMW 61 13 8 364 848 I have plenty if you need it.

Next is to run one 14 gauge power lines from the each seat to the electrical box above the relay carrier. Here is the 14 gauge yellow power line being put into the seat mating receptacle.

Route the power lines forward and up to the relay carrier Disengage the relay carrier from its mounts, takes a bit of fiddling, and let it hang down

Then you can see the two connectors to the electrical box. Disengage them, a grey and a black.

You will connect the yellow power line from the driver seat to pin 25 of the black receptacle in grey connector housing and the yellow power line from the passenger seat to pin 1 of the grey receptacle in the black connector housing. Pull apart the connectors.

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Add a different special terminal to the yellow wire and insert into correct pin location. Driver wire shown above and passenger below. Note this pic below also shows wire from next step in position 2. This terminal is BMW 61 13 6 913 612. I have plenty if you want to do this.

Next run a small gauge wire from electrical control unit black housing grey receptacle pin 2 AND grey housing black receptacle pin 26 and splice both wires into grey housing black receptacle pin 23 wire (red with black stripe). Put heat shrink tubing on the splice

Add the special terminal ends and install them into correct positions in grey and black receptacles .

Plug connectors back into electrical box, reinstall relay carrier, etc.

Get the wiring done first before letting dealer program the AC control unit and change coding in other modules; because you may set the airbag light on while working on the seat connectors, so that they can clear the airbag light at the same visit without additional charge. The dealer must enable seat heating in a couple of software modules. Special connectors BMW 61 13 8 364 848 BMW 61 13 6 913 612

Thank you Steve! Really appreciate you re-posting this valuable and detail project to this forum again.

+1 nice post!

here is pdf for wiring diagrams

Planet-9 Porsche Forum www.planet-9.com this post gave me the info I needed to contact the tech for the part numbers for the BMW connectors

Very good, it's remarkably similar to the process in the 981 . 👍