WoodyFromBama

Driver-side seat heaters not working. All three heating elements are good but the thermistor circuit reads open. I can't find the left hand front cushion heater for sale anywhere -- the thermistor is inside it -- so I'd like to try to repair it. If I can get an appropriate thermistor I'll replace it.

But to do so I need to know the [general specs] for the thermistor in that element. I know that the resistance range is between 850 ohms and 11.5 K ohms and that it is intended to help control the seat heater between 30C (98F) in the Low postion and 42C (108F) when in the high heat position. Also, rather than cut the seat bottom too much looking for it, it would be nice if I knew approximately where it is located in the heating element.

Has anyone opened up one of the seat cushions and actually seen the thermistor? Does anyone know what the specs for it are? Just knowing whether its PTC or NTC (resistance goes up with heat or resistance goes down with heat) would be helpful. At the moment I'm assuming the latter but that doesn't completely jive with my observation that it is currently open/infinite resistance and that's the reason it isn't coming on.

Byron

iTrader: (1)

If you have a junkyard close by, the CTS base and srx share the same seat electronics from what I see.

Maybe hit a junkyard and open one up and see?

Not sure if this will help any, but a fairly detailed description and theory of ops can be found here.

​​​​​Seat heat not working (driver's side) - Can anyone help me troubleshoot? https://www.cadillacforums.com/forums/showthread.php?t=221239

​​​​-Byron

WoodyFromBama

Hy Byron and thanks for the reply. The info about the SRX and the V sharing the same seat electronics will be very helpful -- certainly will expand the range of possibilities. Here in the Seattle area you just don't find the Vs in a junk yard.

Thanks for the troubleshooting reference. That was what I used to troubleshoot and figure out that our thermistor was open.

Best regards,

WoodyFromBama

Hi again Byron. I just called the Cadillac dealer in Bellevue, WA and, using the last 8 of the car's VIN to look it up, he said the heater cushion is still available from GM and the part number is 25764214. I've looked that part up on several online seller sites -- it looks like nearly all are using the same parts catalog -- and they all find that part for the CTS 4 door and V 4 door along with the SRX but when I specify the V or enter the VIN to check fitment it says that it does not fit. Have no idea why it does that but am happy to find that a new part is still available from GM.

I'll go with that instead of repairing what I have -- though that would have been fun to do.

For now I'll consider the question answered. Thanks again for your help.

WoodyFromBama

While I didn't find a new heating element while searching by VIN or, for that matter, car attributes, I was able to find one. I called the Cadillac dealer and they gave me part number 25764214. I had already run across that p/n but when I would enter the CTS-V to check fitment it would say that it did not fit. But if you look at the list of cars that it would work with the V was listed. Go figure...


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MN_V

iTrader: (5)

Is there a back heater?

WoodyFromBama

Hi MN_V. If you mean back seat the answer is no. If you mean the back of the two front seats the answer is yes. Each seat has three heating pads/elements - bottom-front, bottom-back and back -- and they are wired in series -- like Christmas tree lights, one fail all fail. In my case all of the heating elements are good but the thermister that controls the on/off duty cycle of the heaters opened up and it is physically located in the bottom-back heater pad.

2006 Cadillac CTS-V Seat Heating Elements

MN_V

iTrader: (5)

Thank you - yes that clears it up. I noticed the thermostat part only showed a single bottom heater so it is helpful to see how it is setup.

WoodyFromBama