Heated seats.......

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS
Completed most of the wiring, and just waiting for some harness parts to come in.

One question, on the wiring diagrams, does the "30 unswitched power" refer to the "30" or the "30A" power source?
What wiring are you referring to? I didn't see what approach you're taking.

As an update to my quest, I just picked up a complete 2000 Jetta that has only 118k miles (gasser w/bad engine): paid $400. The car is immaculate. Seats, just what I wanted- beige, cloth heated (exact same pattern), are in excellent shape. Seller (it was his daughter's car) says that the driver's seat heater wasn't working- I figure I can resolve this.

I plan on using this wire harness:

https://www.kufatec.de/shop/en/retrofits/seat-accessories/seat-heating-harness-vw-audi-seat-skoda
 
Joined
Jan 8, 2011
Location
Banff, AB
TDI
2003 Golf TDI (MK IV - ALH)
Sorry for the confusion, I'm using this diagram and referring to the power sources noted near the bottom of the diagram ("30 unswitched power").


Ok, I think the bently diagram is confusing. Too much info for what I need. I've put together this diagram to simplify things. Let me know if I've made any errors.
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
No clue what 30A means, other than 30 amps.

30 is a constant 12v power source. As the diagram mentions, it's unswitched.

-Todd
 
Joined
Jan 8, 2011
Location
Banff, AB
TDI
2003 Golf TDI (MK IV - ALH)
Right. So on the power studs under the dash, there is a "30" and a "30A".


Which one should I use to draw power for the heated seats? I'm using the wiring diagram shown on post 152. Thanks.
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
In this case, it appears it's just a separate feed from the battery. I'd confirm with the Bentley, and if so, choose whichever.

-Todd
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS
Managed to tear into the driver's seat after finding that the thermistor circuit tests "open." Most seem to state that it's the thermistor wires that break, but having the seat apart I'm not seeing any signs of breakage:



I cut just to start tracing the wires. Hard to see, but the wires seem perfectly fine, though who is to say whether they couldn't be broken inside the insulation (I've read that they tend to break out-right). I'm hesitant to cut up any further unless I'm certain that the thermistor is shot: I'll be cutting right over the elements themselves. Not certain how the wires connect down below; seem to disappear into some clumps of black glob-y material, which I'm also a bit hesitant to mess with.
 
Last edited:

SilverGhost

Veteran Member
Joined
Mar 25, 2005
Location
Back in So Flo - St Lucie
TDI
'05 Golf - totaled :(, wife's '13 Beetle - buy back, TDIless
No clue what 30A means, other than 30 amps.

30 is a constant 12v power source. As the diagram mentions, it's unswitched.

-Todd
I know this is old post, but that does NOT mean 30 amps. DIN standard wiring in German cars 15 is switched ignition, 30 is battery +, 31 is ground, 75/x is load reduction (aka accessory).

In this case 30a is a secondary battery feed.

Jason
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
DIN standard wiring in German cars 15 is switched ignition, 30 is battery +, 31 is ground, 75/x is load reduction (aka accessory).
I'm familiar with German wiring, but based on the diagram provided, there was no "30A", which was confusing. My response included:

30 is a constant 12v power source. As the diagram mentions, it's unswitched.

In this case 30a is a secondary battery feed.
Jason

Once the pic was posted, it added clarity, which I replied:

In this case, it appears it's just a separate feed from the battery.
-Todd
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS
Following up to my previous post above (#156), I sliced further down and found one of the wires to the thermistor broken. All has been back together and working in my car for some time now (awesome this winter!). It's looking like I now need to do the same repair to the driver's seat in the wife's car (which is what brought me back here). I had thought that I'd seen someone do such a repair in-car, popping the back of the lower seat cushion loose, but have been unable to find (just to verify that it does work, that it's the same style of seat); if anyone is familiar with that info (not sure if it was on this site or not- thought it was) I'd appreciate any tips to where I can see/find it.
 

EricMoreira

New member
Joined
Oct 19, 2021
Location
Brasil
TDI
Bora MK 4,5
[QUOTE = "kbrenny, postagem: 4278504, membro: 80302"]
Não me lembro das cores dos fios, mas vou tentar explicar.

Existem 4 fios que vão para os elementos de fábrica da VW:

poder para os elementos
aterrado para o elemento
fio de sinal do termistor para o interruptor
aterramento para termistor

Os dois aterram ambos no mesmo ponto.

Usei os 4 fios de fábrica e executei o + e - que iam para os elementos de fábrica e os corria para os elementos do mercado de reposição.

Em seguida, executei o fio de sinal e o aterramento que iam para o sensor de temperatura de fábrica e os conectei ao termistor que instalei. Instalei o termistor no mesmo local em que foi instalado de fábrica, centro traseiro da almofada inferior.

Os elementos de reposição que usei eram uma configuração de elemento de 2 fios e, embora também tivessem algum tipo de sensor / termistor, era conectado ao próprio elemento. Eu os deixei no lugar e meus elementos ainda funcionam bem com eles no lugar.

Se os sensores / termistores que vieram com os elementos falharem, provavelmente irei removê-los e conectar os fios que estavam indo para eles.
[/CITAR]
Olá
Estou instalando aquecimento no meu Bora com kits de elementos em carbono (2 assentos, 4 elementos) com interruptores OEM vi que vc fez essa instalação, minha duvida é a seguinte:
tenho que retirar o protetor térmico de cada elemento e colocar um termistor de 6,8k em cada elemento. =? como foi feita a ligação? pode me ajudar mostrando como vc vez? ea temperatura do interruptor funciona em todos os niveis? 1, 2, 3, 4 e 5
 

EricMoreira

New member
Joined
Oct 19, 2021
Location
Brasil
TDI
Bora MK 4,5
[QUOTE = "hremus, postagem: 4203425, membro: 150758"]
sim. Instalei muitos kits aquecidos de reposição com interruptores OEM. Você não precisa de todo o kit, apenas os elementos de aquecimento. Você pode comprar apenas estes (são mais baratos). Eu recomendo que você use o elemento do tipo carbono. Para 2 lugares custa cerca de 50Euro. Alguns deles incluem o termistor (4 fios). Quando comecei a instalar bancos aquecidos no mercado de reposição em 2007, usei no meu carro um kit da Waeco. Após 4 anos, os elementos de aquecimento quebraram. Substituí-os por elemento de aquecimento do tipo carbono.
Para instalar, você precisa remover os assentos do carro, remover o estofamento, instalar o elemento de aquecimento. De cada assento você passa 3 fios (energia de aquecimento, sensor, aterramento) para os interruptores.
[/CITAR]
Olá
Estou instalando aquecimento no meu Bora com kits de elementos em carbono (2 assentos, 4 elementos) com interruptores OEM vi que vc fez essa instalação, minha duvida é a seguinte:
tenho que retirar o protetor térmico de cada elemento e colocar um termistor de 6,8k em cada elemento. =? como foi feita a ligação? pode me ajudar mostrando como vc vez? ea temperatura do interruptor funciona em todos os niveis? 1, 2, 3, 4 e 5
 

Diesel900

New member
Joined
Dec 28, 2021
Location
Hungary
TDI
Seat Toledo 1m2
Hi!

I have a Seat Toledo (Just like Leon 1M) and i retrofitted heated seats (it was not prewired), and i wired it up just like this in this thread (i used that diagrom from above, the oem one).
It seems to work, but when i turn the dashboard switch to 5 it is not gettin too hot. What do you guys think what is the problem? Maybe the switch? It is not getting enough power? Or what...i worked a lot on it and i want to be it as good as possible. If i want to measure the voltage that the switch controls, and i roll the switch the voltage should move, right? i mean, if on position 2 the voltage is 4, at position 3 it should be higher like 6.

Thank you for your time and help, and sorry for my bad english i'm from Hungary :D
Thanks, David.
 

kbrenny

Veteran Member
Joined
Jul 9, 2008
Location
Mora, MN
TDI
2002 Jetta wagon TDI
The power from the switch to the heating elements is controlled internally by the circuitry inside the switch. The switch reads the signal from the "thermistor" or temp sensor and then sends the appropriate power to the heating elements. The power sent to the heating elements is not as simple as increasing voltage to increase temperature. The power sent from the switch to the heating element is a "pulse" that varies in duration and frequency to accomplish the desired temperature. This is why the "thermistor" or temp sensor is wired back to the switch. This is so the switch knows how to change the frequency and duration of the "pulses" it is sending to the element. I do not remember who, but someone much smarter than me from this forum explained it to me once and it all made sense. Understanding the function of the system helped me enormously when I was installing aftermarket heating elements in my car but using the factory wiring and switches.
 

Diesel900

New member
Joined
Dec 28, 2021
Location
Hungary
TDI
Seat Toledo 1m2
So what do you think, to solve this problem (the seat is not getting too warm) change the switch, or what would be the solution? I have the factory heating elements in the seat, and i wired it up just like the diagram above (the bently diagram)
 

kbrenny

Veteran Member
Joined
Jul 9, 2008
Location
Mora, MN
TDI
2002 Jetta wagon TDI
Do both switches / seats perform the same? If not, it could be a faulty switch.
I have also read that there is a difference in switch part numbers from leather seats to cloth.

Another possibility is the "thermistor" or temperature sensor is bad. While this is part of the factory heating element, and not available through VW, there is an acceptable aftermarket replacement mentioned in this thread. Search this thread for "mouser" (online retailer who sells it) and it should pull it up with the part number. Also check the wires going to the thermistor are not broken or compromised in any way.

My Heated leather seats do not feel very warm to the touch when set to 5, but if you are sitting in them for more than 5 to 10 minutes they get fairly hot. I personally wouldn't want them to get any hotter.
 

Diesel900

New member
Joined
Dec 28, 2021
Location
Hungary
TDI
Seat Toledo 1m2
The second hand switch that i bought is not the best i think, the passanger side switch does not even work…if i put the driver side switch to the passanger it warms the seat just like the driver side, no too warm barely perceptible. I have to buy new switches because of the passanger side, so i will try the change the switch method.
The thermistor is in the seat, under the leather? Or where it is?
I have read that there is 2 type of switches, cloth and leather but on my switch there is no B or D mark for leather or clothe, only the part number is on it.
 

kbrenny

Veteran Member
Joined
Jul 9, 2008
Location
Mora, MN
TDI
2002 Jetta wagon TDI
The thermistor is actually part of the heating element, which is why it is not available thru VW as a separate part number. I cant remember if it is part of the upper or lower element. I think it is likely to be on the lower, but I could be wrong. You can trace the two smaller gauge wires to find which element the thermistor is in. You can actually install a new thermistor without removing the seats or elements. with the seat back leaned all the way forward, and the seat itself all the way forward, going in from the rear door, find the smaller gauge wires going to the thermistor on the back of the seat near the center, you can cut the wires (as close to the heating element as possible) and soldier in the new thermistor and just tuck it under the fabric and on top of the element (it is very small and thin). Place the new thermistor under the fabric just at the very back of the seat cushion. I have seen quite a few instances where a new thermistor fixed a non functional heated seat (although the switches are the most common problem)
 

Diesel900

New member
Joined
Dec 28, 2021
Location
Hungary
TDI
Seat Toledo 1m2
So my electrician friend solved the problem. It was the switch. The switch has a potmeter, it is the switch that have 5 options. Both switches had issues with it. Because of the usage and the push when you turn it, the potmeters leg just broke, and didnt switch. In my driver side when i turnt it to 5 it was about 1-2, because after that the potmeters leg didnt connect. In my passanger side it was just broke so there was no switching. It is an easy fix, and dont need to buy new switches, the circuit is flawless in both sides, and it dont useally fail. Hope you can understand it, if you have any questions feel free to ask me, and sorry for my bad english :D and here is a picture of the seats, i think it did worth to do all the work :D , it is from an american volkswagen mk4 jetta (here in hungary its called Bora). It is pretty hard to find a well maintaned 17 years old leather seats.
 
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