[V8] Seat Heater switches

Tue Feb 3 11:04:47 PST 2015

Huw,

Nice work!

The only other thing you may wish to consider is a latching relay to
initially enable the seat heater circuits, this way when the ignition
switch is shut off, the seat heaters are cycled off. I say this for two
reasons. Folks can leave the seat heaters on, and they will run in the V8
with no occupant in the seat. Not a problem, other than this is a current
draw you don't want on continually.

Secondly, as in the example of my wife's Grand Cherokee, she constantly
leaves the damn seat heater on high, and I don't remember to switch it off
when I drive it until after I feel my butt getting hot - very annoying!
LOL! I need to wire in some latching relays with momentary activation
switches to fix this design shortcoming.

The only advantage of the "always on" system is for those who use a remote
start system, to also have warm buns when they initially get in the car
after it has been remote started. To me the advantages of having them shut
off automatically, especially from both a safety and current draw
perspective outweigh the stock design. Many new vehicles are set up through
their control units to operate this way because manufacturers are looking
for any way to limit current draws and thereby increase economy: remember
any additional load placed on the engine (to drive the alternator and
produce current output) requires horsepower/fuel. Current charging systems
are computer controlled for this reason to literally shut off the
alternator when limited to no output is needed.

Regards,
GT

On Sun, Feb 1, 2015 at 8:31 PM, CavalloGT <cavallogt at gmail.com> wrote:

> Nick,
>
> I don't have a schematic handy, nor do I have a vehicle readily available
> to test, but based upon what you have described, the seat heater switches
> are very possibly nothing more than potentiometers used to vary a voltage
> input signal to the relay, and then the relay outputs a varying duty cycled
> amperage to the seat elements. The sensors in the seat elements are most
> likely nothing more than bi-metal switches that open to limit max heat.
> I'm totally guessing here, but again based upon what you said that would
> be my SWAG at it (Scientific Wild Ass Guess). :>)
> This of course means that the "relay" is more than just a common ISO
> (International Standards Organization) rectangular 4 or 5 pin relay, but
> instead has some add circuitry built in ala the intermittent wiper "relay".
>
> Keep us all posted. Butt warmers are a nice feature, in fact within the
> past week, based upon an email I received from my subscription to Autoweek,
> I'm planning to use a spare driver's seat from one of the V8 parts cars I
> had to build a PC Racing Sim Rig, including the power adjustments, with
> memory and the butt warmers, or bun warmers as some call them.
> Many, many moons ago when the very first racing sims came out, I got a
> steering wheel that attached through a "game port", but soon lost interest
> as the early sims were pretty unrealistic and therefore pretty boring. That
> was in the late 1980s.
> Now, holy crap, how things have changed! The email from Autoweek featured
> the new Ford GT, and the teaser for Forza Motorsport's new sim for XBOX
> One. I don't own an X Box, and never will, but the point is that after
> seeing how far current racing sims have come, I'm hooked!
> If you think about it, the military has been using them for years to train
> pilots, and now (probably for some years) top racing teams use sims for
> their drivers to hone their skills in learn in ng specific tracks.
> I found a reasonably priced option for a DIY sim rig with Ricmotech.com
> IMHO it's an easy and cost effective way to give it a shot and not have a
> big investment in something that you are not sure you'll stick with. For
> someone like me who cannot currently afford a race car, this is an
> attractive option that can grow into something bigger and better as desire
> and funding allow.
> The thought of racing others through the online site iracing.com is even
> more attractive.
> I've been flying RC planes on my "Realflight" sim for years, but never
> gave auto racing sims a second thought due to my experience from years ago.
> Silly me!
> This is going to be interesting!
>
>
> Sent via the Samsung Galaxy Note® 4, an AT&T 4G LTE smartphone
>
>
> -------- Original message --------
> From: Nicholas Miller <chance9121 at gmail.com>
> Date: 02/01/2015 12:33 PM (GMT-05:00)
> To: quattro at audifans.com, V8List Fans <v8 at audifans.com>
> Subject: Re: [V8] Seat Heater switches
>
> This does look like a big endeavour.  I'd like to test at least one switch
> and see what the rotary wheel does, vary voltage or current.  I checked my
> schematic for at least one set of seats, on my seats the temperature sensor
> is in the heater coil, all it gets is 2 wire signal from the switch, and
> everything else is sorted in the seat.  I think that may work, but in this
> case you would not get more heat, just variability between the current
> setting and off, maybe.  Best way to check would be to see what my current
> switch puts out for voltage, check inline current on the heater circuit,
> then check voltage output on the Audi switch and wire it inline to see if
> it varies current when inline.   I think it could work, even though not
> like it does in the original system.
>
> Surely, the rotary switch does something with voltage/current even if it
> doesn't have the final say in the circuit, correct?  I understand in the
> end it seems to just signal a relay that then varies the power/heat level
> to the seat in the audi system, so my main question then would be how much
> current can the switch carry?  Probably not a ton, in this case.
>
> On Sun, Feb 1, 2015 at 8:27 PM, Nicholas Miller <chance9121 at gmail.com>
> wrote:
>
> > I'm in minnesota, 56560
> >
> > On Sun, Feb 1, 2015 at 1:59 AM, <jlagnese at massed.net> wrote:
> >
> >> Yes, I have several. I need to check if  they are left and right pairs.
> I
> >> am in Maine. Where are you?
> >> John
> >>
> >> -----Original Message----- From: Nicholas Miller
> >> Sent: Saturday, January 31, 2015 4:51 AM
> >> To: V8List Fans ; quattro at audifans.com
> >> Subject: Seat Heater switches
> >>
> >> Hey everyone,
> >>
> >> Does anyone have some pairs of Heated seat switches around?  I want to
> >> retrofit a few of my cars with these Audi/vw switches, as I have a 1
> >> position button on my heaters for right now.  I'd like to try and
> retrofit
> >> the Audi switch into the car.
> >>
> >> Has anyone done this before?  I'm not sure if it will work, but in my
> head
> >> it should be simple, I'm assuming its Vin, Gnd, Vout, and Backlight Vin,
> >> and the switch operates like a potentiometer.
> >>
> >> P.s.  The candidates are 2 MX-5s, a Mazda 3, and a Mitsubishi Eclipse.
> >> Cause its cold up here in MN.
> >>
> >> Cheers all,
> >> Nick
> >> _______________________________________________
> >> quattro mailing list
> >> http://www.audifans.com/mailman/listinfo/quattro
> >> http://www.audifans.com/kb/List_information
> >>
> >
> >
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-- 
*Thanks,*

*ProfessorGT*