Heated Seat Retrofit Wiring Help Sought

[askopp]

I am in the process of installing heated seats into my 2000 996 Coupe.  I purchased an aftermarket heated seat package that came with the pads, the wiring and the switches.  I want to use the Porsche factory switches though, and I plan on placing them not in the batwing but in the center console where the two dummy plates are.  I've read Dennis Vogel's excellent write up and searched the forums, but need help with the wiring.  The Porsche factory switch has five leads (ground, three to the seats (hi/low/off?), and one to the relay).  BUT, the aftermarket switch has just four leads  (hi, low, ground, power)?.  And the switches seem to operate differently.  Whereas the Porsche switch returns to "home" after being depressed, the aftermarket switch is more like a light switch (on/off).  Pictures of everything are below.  So, the $64,000 question is, how do I wire up the Porsche switch with the four leads from the aftermarket one?  Do I need to bring another line to the Porsche switch?  If so, where am I tapping it into?  Thanks so much in advance for the help.   Andrew

[Loren]

 

This should help...

 

[creekman]

It sounds like you already know where you want your seat heater switches to be placed, I had a couple of empties on the horseshoe surround so moved mine there...  Made a new bat wing filler.  I like this since all the switches are in one place.  You'll note that I exchanged places with the cubby and A/C control panel.  Again I wanted all the business of switching and controls seamless to one another.  I did have to section the cubby to fit, but it wasn't much good anyway other than a place for your iphone.  

 

 

[askopp]

Thanks Loren for the diagram.  This is helpful...somewhat.  My problem is that I have at best only a "dangerous" level of knowledge of schematics reading and wiring.  I found what is likely to be the wiring diagram for the aftermarket switch.  See attached.  Can someone translate this and the Porsche schematic and give me a sense whether I can wire in the Porsche switch instead.  And if so how.  Specifically what wires from the Porsche switch go where on the aftermarket diagram?  Thanks much.  Andrew

[KevinH90]

I'm not an expert on electronics, so please use my advice with caution.  I did use Denis Vogel's instructions to install heated seats in my car, and based on that experience, I am offering these suggestions.

 

Here's a link to a picture of the seat heater relay with the wiring:

Seat Heater Relay with Wiring

 

There are 7 wires:

 

Red/White

2 brown

Red/yellow

Yellow/white

Black/yellow

Red/violet

 

The red/white is power and the brown is ground.   The other wires are the control wires from the switches.

 

The red/white wire leaves the relay and goes to a connector that has the wire for routing current through the heating pad in the seat back.  Another red/white wire comes out of the connector and goes to another connector to provide current for the heating pad in the seat bottom.  A brown wire exits that connector and runs to the ground in the relay.

 

I think what you need to do is connect the red wire (which I think is power) in your heating pads to the red/white wire from the relay and the black (ground) wire from your heating pads to the brown wire of the relay.  You want to hook the heating elements for the seat back and seat bottom in series so that the current flows through one and then the other.

 

The control wires will be connected as outlined in Denis Vogels' instructions.

 

[dark_n_deep1]

Hi Askopp, trying to do the same thing as you. After market heated seats with OEM Porsche seat heating buttons in the center console. Were you able to do it and do mind sharing details.

Thanks.

[John Dollarhide]

The porsche switches are momentary so you need a different relay, one that is latching or magnetic or flip flop or something like that. I'm still doing the research myself.