Heated and cooled seating.......I did not know this..

[mwilson]

I am killing time until our server at work backs up so I figured it would be a good time to share what I learned this week...

You know how I ramble so here I go.....

Hoopty was making my hip ache a little (and Hoopty is supposed to be all about comfort ya' know) as the drivers seat cushion was beaten down by a previous owners hefty bottom...cover in good shape so I checked out the GM parts system for a seat breakdown. Lo and behold a new cushion was about $50.00 so I ordered one up. The cushion sat in the shop for about 2 months awaiting my attention so I tackled the project Sunday afternoon.

A little more involved than tearing the seats out of either of my Rams simply because of seat mounted air bags and tighter quarters but I got it out and didn't set off a bag so I must have discharged the capacitor correctly..

Some plastic trim and a gob of switches around the perimeter with some very tight clips, but got it apart and didn't break anything. Once I got to the basics the seats would appear to be Lear and are are constructed just like my '06. Released the cover on both sides and the front, then pulled the old cushion out and replaced it with the new one.

Routine so far, right?? Nodding off yet???

Now this is what got my attention....The seat heater in the cushion didn't work very well and the cooling was so-so as well. It's a used car but I figured while I had the lower cover off that I would look around for a burned spot or something in the heating pad that I could salvage or order a Rostra pad in the near future and do a re-work.

Well, couldn't find any wires or burned spots...??? WTH??

It was getting late and cold so I buttoned it back up in the shop and lugged it outside to the car. Put it back together by the glow of a trouble light and an LED flashlight.
Grabbed the dog and went for a test ride.

OOOOH it was so comfy, just like sitting on a cloud. Got down to the main road and turned the seat heat on. After about 5 minutes my butt was hot!!! Not slightly warm but Hot. I had to turn the seat heat down a notch. Well, still thinking electric grids I figured that I had wiggled enough stuff to make a temporary connection and it wouldn't last long. Got in and out of the car several times and still had awesome cushion heat.

Figure out why yet????

Do you want to know???

 

[RustyJC]

OK, Mike, I'll bite. Why?

Rusty

 

[mwilson]

This is what I learned once I got home. GM heated and cooled seats work on a heat pump principle. By reversing the polarity inside of a "TEDS" unit that resides in the seat base mounted blower the seat either provides heat and sheds cold or vice versa depending on the mode selected. So there is no grid or anything of the kind.

What had happened due to the large bottom of the previous occupant is the foam had broken down inside and once my bottom sat on it the internal ventilation chambers closed off.

I had noticed when using the remote start the seat cushion was warm when I got in the car and then kinda' cooled off.

So I really have some respect for this engineering and am wondering if RAM is using the same system. Miles ahead of heater grids that like to break.

I have saved the old cushion and will grab some pictures in a minute but I need more coffee first.....

 

[Cooper_D]

Ok, so what you are really saying is "I could not figure out why it only worked great when my wife drove it and just ok when I drove it":-laf:-laf:-laf

Oh I am so deleting this post in a hour so read fast!

 

[mwilson]

Ok, so what you are really saying is "I could not figure out why it only worked great when my wife drove it and just ok when I drove it":-laf:-laf:-laf

Oh I am so deleting this post in a hour so read fast!

Exactly!!!!

 

[mwilson]

This is where the underseat blower connects to the underside of the cushion...

 

[mwilson]

Anyone that has done the cushion fix on a 3rd Gen recognize this scenario???

View attachment 90464

 

[mwilson]

This is how the air gets to the perforated seat cover....

 

[mwilson]

This depression is directly over the connection underneath.

 

[SnoKing]

Some old man keeps sticking his hand in your pictures!!!

#ad

 

[mwilson]

Some old man keeps sticking his hand in your pictures!!!

#ad

I know, the wrinkled up ol' *******.......

 

[mwilson]

That depression, probably from a combination of heat and butt pressure is what was shutting off the air flow.......

 

[mwilson]

The ductwork underneath, these are really quite a clever set-up.....

 

[mwilson]

So even though this is not a RAM I am pretty confident that the same system is in use where Lear is probably the seat vendor for RAM as well as GM.

So when the 4th Gen crowd begin to have heated / cooled seating issues this thread will be here lighting the way......

Mike.

 

[TFucili]

So when the 4th Gen crowd begin to have heated / cooled seating issues this thread will be here lighting the way......

Mike.

You're a regular beacon, Mike!

 

[mwilson]

I'm somethin' all right........

Here is an exerpt from the DTS service manual, again just for reference as to how they work. I bet this is Lear info...

"AIR CIRCULATION
When the heated/cool seat switch is pressed to initiate operation of the climate control seat (CCS) system, cabin air is drawn through the heated/cool
ventilation module air filter, then directed through passages in the foam of the seat cushion and seat back to the seat's occupant. In order for the CCS
system to operate to its optimum performance, it is crucial to have unrestricted air flow through the system. A dirty or restricted air filter, the blockage
of an exhaust air duct, a misaligned heated/cool ventilation module, or incorrect foam installation of the seat cushion or seat back will all have
negative effects on CCS operation.
HEATED/COOL VENTILATION MODULE
Each heated/cool seat has 2 ventilation modules, one located under the seat cushion and one located in the seat back. These modules are controlled by
the climate control seat module (CCSM). Each ventilation module contains a thermo-electric device (TED), a temperature sensor, and a blower motor.
The TED and temperature sensor are mounted downstream of the blower motor. Each TED consists of a circuit of positive and negative connections
sandwiched between 2 ceramic plates. Each ceramic plate is equipped with copper fins for heat exchange. The air flowing past these fins is either
directed as conditioned air into the seat cushion and seat back, or directed into the cabin as waste air.
A TED is essentially a solid state heat pump that is used to heat or cool the air supply to the seat cushion and seat back. When voltage is applied to a
TED, one side releases energy as heat, while the opposite side absorbs energy and gets cold. When the polarity of the current flow to the TEDs is
switched, the hot and cool sides of the TED reverse.
During the following climate control seat system description and operation, the TEDs, blower motors, and temperature sensors will be referenced
independently even though they are all packaged together as a module.
CLIMATE CONTROL SEAT (CCS) SYSTEM
The CCS system consists of two heated/cool ventilation modules and one climate control seat module (CCSM) that controls both the driver and
passenger heated/cool seats systems. The CCSM is mounted below the front passenger seat cushion. It receives power from both, battery positive
voltage and ignition 3 voltage.
Once a CCS system is activated, cabin air is drawn through the seat blower motors and directed across the fins of each of the thermo-electric device
(TED) located under the seat cushion and in the seat back. The air is either heated or cooled as it passes over the TEDs. This conditioned air is then
directed through channels in the foam of the seat pad and through small holes in the seat cover to the occupant. Once the system is activated, the
CCSM uses a set of algorithms to control the temperature of the selected heating or cooling modes."

Mike.

 

[mwilson]

Now I need to find the seat air filter...still not done learning about this from the look of it.
Must be built into the blower module.....

 

[TFucili]

Reading that reminds me of that drug commercial, "I am M-I-K-E, and I have C-C-S with T-E-D"

 

[mwilson]

Bob and Carol and TED and Alice.........