Need help with wiring heating for 997 seats
10-07-2012, 02:31 PM
#1
Need help with wiring heating for 997 seats
I am installing a set of seats out of a 2006 Cayman into my car. From my research, these are the same seats that were used in 997s. I have the physical installation taken care of and wiring for the 12-way power is just about complete. These were memory seats, so I had a few extra hoops to jump through with wiring adjustments for the driver's side. The last part that I need to complete is to make the connections for the seat heating. I connected 12v to the heaters and they heated up and seemed to stop heating when I got out of the seats ( measured seat temps with IR thermometer). Seats were not installed when I did this, they were sitting on the garage floor with an external 12v source. I have done a fairly extensive search of RL and Planet9 archives to try and figure out connection of the seat heaters, but have not found the specifics I need to make these connections. The questions I am looking to answer are:
What equipment exists in the seats (if any) to regulate temperature? I looked at the PET diagrams and didn't really note anything except for the heater elements themselves in the seat, but this doesn't help to explain the seats not heating when I got out of them. Maybe I was just seeing a faster conductance of heat when my weight was pressing down vs. a relative "insulating property" of foam that's not compressed?
I will be connecting to a switched power source. Any experience out there with which source to tap into?
How do I wire in the switches? Do I need to get a relay between the switch and the heater (any wiring diagrams available?). I have a couple of generic 3-position seat heater switches (middle off, rock either way for hi or lo, 3 connections on back plus a wire for power to the LED indicator) so I would prefer to use these, assuming they will work with this application. If I can't use these switches, what switches do I need and where can I get them?
Is there anything else that I have missed? Any help from those who have done this is greatly appreciated (nile13 has already provided some great info. Thanks Mike!) I plan on posting a DIY for this once I am done. The seats themselves are very nice and they are a straightforward install once you understand how.
What equipment exists in the seats (if any) to regulate temperature? I looked at the PET diagrams and didn't really note anything except for the heater elements themselves in the seat, but this doesn't help to explain the seats not heating when I got out of them. Maybe I was just seeing a faster conductance of heat when my weight was pressing down vs. a relative "insulating property" of foam that's not compressed?
I will be connecting to a switched power source. Any experience out there with which source to tap into?
How do I wire in the switches? Do I need to get a relay between the switch and the heater (any wiring diagrams available?). I have a couple of generic 3-position seat heater switches (middle off, rock either way for hi or lo, 3 connections on back plus a wire for power to the LED indicator) so I would prefer to use these, assuming they will work with this application. If I can't use these switches, what switches do I need and where can I get them?
Is there anything else that I have missed? Any help from those who have done this is greatly appreciated (nile13 has already provided some great info. Thanks Mike!) I plan on posting a DIY for this once I am done. The seats themselves are very nice and they are a straightforward install once you understand how.
10-07-2012, 04:05 PM
#2
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Rob, first of all, please keep all teh info and post everything you can after you are done. Pics, wiring, everything. You know these info is impossible to gather.
AFAIK there's absolutely no heat controls in the seat heaters themselves. They are just wire that gets hot depending on input. Besides that there's a heater relay under the seat (at least on 996 seats there is, I believe it's the same for 987/997 seats). 996 switches are interesting. They are momentary rocker switches. The "on" side gets pressed ones to get high heat, once more to get low heat. The "off" side gets pressed ones to turn the heat off. Also, and this is important, the heat goes off once the ignition is turned off. So I believe that all the primitive "logic" of that setup is actually in the relay.
Now, the reason I say this is because I think that it's possible to control 987/997 heat with the same 996 or similar switches. 997 heat is actually controlled by a computer from the switches on CCU panel. But if the seat heat relay in on the seat and similar to a 996 on... I think it might work. So I'd start by finding that relay and comparing it to a 996 one.
Sorry for being vague. It's been a couple of years since I've fought with this myself and even then I did not figure tit out and went with heated 996 seats at the end.
AFAIK there's absolutely no heat controls in the seat heaters themselves. They are just wire that gets hot depending on input. Besides that there's a heater relay under the seat (at least on 996 seats there is, I believe it's the same for 987/997 seats). 996 switches are interesting. They are momentary rocker switches. The "on" side gets pressed ones to get high heat, once more to get low heat. The "off" side gets pressed ones to turn the heat off. Also, and this is important, the heat goes off once the ignition is turned off. So I believe that all the primitive "logic" of that setup is actually in the relay.
Now, the reason I say this is because I think that it's possible to control 987/997 heat with the same 996 or similar switches. 997 heat is actually controlled by a computer from the switches on CCU panel. But if the seat heat relay in on the seat and similar to a 996 on... I think it might work. So I'd start by finding that relay and comparing it to a 996 one.
Sorry for being vague. It's been a couple of years since I've fought with this myself and even then I did not figure tit out and went with heated 996 seats at the end.
10-07-2012, 08:31 PM
#5
So, pardon my ignorance on heated seats, but need I only wire in the switch for each seat, since there is a relay in the seat already, or do I need to get a separate relay? Any idea if the switches I have will work? (I'll be doing some testing on this tomorrow anyway).
Thanks again for the support, Mike. Ed too. I do plan on a complete documentation of my project. There is a fair amount of information out there on doing this, just not comprehensively in one write-up. This is a great mod too, for a daily driver like mine.
Thanks again for the support, Mike. Ed too. I do plan on a complete documentation of my project. There is a fair amount of information out there on doing this, just not comprehensively in one write-up. This is a great mod too, for a daily driver like mine.
