rconnon

I know a bunch of folks have done this, the data / instructions on the process, wiring, switches to use etc is quite fragmented so I was hoping someone who's

1) bought switches
2) wired them up
3) has this working

Can PM me with the instructions needed and I'll compile a how-to -- or if its documented in a thread please post!

I've read the following posts,

https://rennlist.com/forums/993-foru...s-install.html

https://rennlist.com/forums/993-foru...need-help.html

https://rennlist.com/forums/993-foru...s-install.html

I'm specifically interested in knowing if it's possible to bypass the CU Seat Heater assembly in the seat, and wire my switch directly to the heating elements on the seat (is this is a bad idea?)

If i need to go through the seat relay as depicted in the wiring diagram
can I simply just wire in the high-heat and bypass the low-heat setting? I'm looking for a simple on/off setting to control heat to the seats as from what i understand the 996 seats low setting is really a burst heat setting.

Any help getting this up and running would be great and also any recommendations for the best switches to buy for the wiring.

Thanks!

rconnon

Ok, So I think I have it figured out after a few hours of mucking around, help from Mike J and some other threads on the forums

Reference Threads:

https://rennlist.com/forums/993-foru...need-help.html

https://rennlist.com/forums/993-foru...s-install.html

https://rennlist.com/forums/993-foru...s-install.html

This is the process/instructions I used to mount 996 heated sport seats in my '95 993.

The physical install of the sport seats is pretty straight forward, this thread Leland posted is super easy to follow. I installed Manual Slide, Power Back seats so didn't have to deal with the memory / full power seats which are a lot more involved to install

https://rennlist.com/forums/993-foru...stall-diy.html

Now, For Heated Seats

I bought these switches since they look like the Porsche 993 console switches. They came with heating pads, inline fuse and wiring harness. I cut off the heating pads which came with the kit and re-used the connectors.

http://www.ebay.com/itm/Rectangle-Hi...c21eef&vxp=mtr

If you've followed Lelands instructions you will have already cut off the 996 wiring harness under the seat which contains the +12v / Ground for the power back motor, Power to CU Seat relay, Hi/Low heat control wires, etc.



To Power the seat back take the Red and Brown Wires from the wiring harness and attached a standard 14-16guage bullet connector, these fit nicely into the 993 wiring harness. Plug the Red (+12v) into plug #8 and Brown (ground) into plug #7 on the 993 wiring harness. this will power the seats.



993 Seat Harness Pin-out (Thanks MikeJ)

Pin 1 - Ground for heater
Pin 2 - +12 for heater
Pin 3 - Ground for seat cushion height control rear, seat backrest control
Pin 4 - +12 for seat cushion height control rear, seat backrest control
Pin 5 - Ground Lumbar
Pin 6 - +12 Lumbar
Pin 7 - Ground - seat cushion height control front, seat back forward control
Pin 8 - + 12 - seat cushion height control front, seat back forward control

For the heated seats you need the following wires from the 996 wiring harness

+12V to CU seat heater - RED/VIOLET
3 x Brown ground wires
High Heat - YELLOW / RED wire
+12v from CU seat heater relay- YELLOW / BLACK
Low Heat - YELLOW / WHITE (I didnt wire in low heat so i taped this up)

Full wiring diagram here:



Take the Red/Violet +12v and one of the larger gauge ground wires (brown) and put bullet connectors on them just like you did for the seat motor. These will be plugged into the 993 wiring harness to power the CU Seat relay in the seats.



Plug the Red/Violet wire (+12v) into plug #2 and the Brown (ground) wire into plug #1 (Plug 1/2 are meant for the heated seat controls for the 993 so they are on a separate 25amp fuse and is controlled by the ignition)


Now the seat CU has power from the 993 seat wiring harness, we now need to wired up the switch and control wire to toggle on the heat.

Take the Yellow/Black +12v wire from the seat wiring harness and connect the the RED power wire for the switch wiring harness (this is the one that has the inline fuse) - Then Connect the second large brown ground wire from the 996 seat to the ground wire of the switch wiring harness. This will provide the power to the switch and the required power to toggle on/off the heater.



The switches I bought have a power light which gets powered from the +12V coming from the yellow/black power from the seat.

Last thinng to do is connect the high-heat control wire to the switch wiring harness. Cut off one of the connectors from the heater pads that came with the switch kit, we'll reuse these. Take the Yellow/Red wire from the 996 seat harness and connect to the Red wire from the connector you cut off the heating pad, then connect the remaining brown ground wire (smaller gauge of the 3) to the black wire from the connector we cut off the pad.



Thats the last step. Now you need to put the seat in the car, connect the bullet connectors for the power back [+12v to Pin #8, ground to Pin #7] + seat heater [+12v to Pin #2 ground to Pin#1]. Now Plug the Seat wiring harness connector to the switch connector, bolt the seats in and start her up and crank on the heat.



If you have any questions, feel free to PM me.

e3photo

looks great, but I wish I could see the attached images.


Emerald

rconnon

If you right click and open in a new tab they load, previews don't work. I'll post the picks on the forum instead.

nile13

I've PM'd the ebay links to the actual (and cheap) 986/996 switches yesterday. Which should make the heated seat portion a breeze for both Hi and Low heat (that's what I have in my 993 for the past 9 months or so).

But if your install works and produces heat - mission accomplished. Warm *** is a good thing

e3photo

Thanks,
I'll give it a try.


Emerald

rconnon

Fixed images.

rconnon

Got the switches mounted today, they fit nicely next to the parking brake... While i was in there I also found out why my parking brake dash light wasn't working, the wired sensor tab wasn't connected to the handbrake assembly

doberdog

Nice instal, looks great.

Ed Hughes

Nice thread-should be a great reference for others wanting to do this.

ble2011

The switches and install look like factory - exactly the outcome I would prefer. Nicely done.

Knight

Looks great Rob

silvewrc2s

Thinking of doing this, after a search this old thread popped up. Is there any easier way?

quacktoduck

how so easy? if you have the seats the instructions are pretty strait forward. You should look at upholstery or audio shops

nine9six

Rob,
Please say these were 996 hard back sport seats you installed! But regardless, a very clean OEM install on the switches!