Omega Owners Forum

Omega Help Area => Omega Electrical and Audio Help => Topic started by: polilara on 19 January 2022, 13:19:16

Title: Heated FL Front Seats Wiring & Control
Post by: polilara on 19 January 2022, 13:19:16
Hello, read here
https://www.omegaowners.com/forum/index.php?topic=149084.0
and other places too, that FL front seat "heaters aren't known for their durability"...
So mine are broken, too, 2001 FL (Elegance) Tried to check the wiring a bit...
(https://i.postimg.cc/15y6CHD9/20220118-190121.jpg)
So, five Connectors, below is what I think?
Yellow=Side Air Bag
White or Light Gray with Brown and Blue wires=Seat Belt Tensioner
Grey with Brown and Red=Electricity to Standard Seat up&down control motor
Green with Black having Yellow stripe and another Black having Green stripe indicates 11kOhm resistance. Is this the 'heating controller' unit (PTC/NTC) resistor TB discussed in link above? Temperature was +10 degrees Celsius.
Black with Black and Brown, resistance here is infinity so if this is the heater units (in series) one of them certainly broken.
If it is as described above:
1. What should be the resistance of the heater unit when ok?
2. How does the control work, is it On/Off according to temp measurement (1-5) or are there resistors somewhere which gives 5 different Voltages?
3. What is typical place to find failure if heater unit is broken?
Title: Re: Heated FL Front Seats Wiring & Control
Post by: Doctor Gollum on 19 January 2022, 14:59:41
On the heating element itself.

The end of the wiring at the seat connection is pretty bombproof. The heater pad itself flexes and breaks. Shorts cause hot spots and the resistors fail.
Title: Re: Heated FL Front Seats Wiring & Control
Post by: STEMO on 19 January 2022, 15:02:02
I have hotspots on my drivers seat too.  ;D
Title: Re: Heated FL Front Seats Wiring & Control
Post by: Doctor Gollum on 19 January 2022, 15:09:21
I have hotspots on my drivers seat too.  ;D
Matching stains too I shouldn't wonder ::)
Title: Re: Heated FL Front Seats Wiring & Control
Post by: Nick W on 19 January 2022, 15:18:37
On the heating element itself.

The end of the wiring at the seat connection is pretty bombproof. The heater pad itself flexes and breaks. Shorts cause hot spots and the resistors fail.


The seat bases are the same for both front seats. Which means you can fit a passenger one to a driver's seat in a few minutes. They get a lot less use, so the heat pad is much more likely to work, the trim won't be as worn, and the foam will be in better condition.


This was one of the better things I did to my car.
Title: Re: Heated FL Front Seats Wiring & Control
Post by: polilara on 19 January 2022, 17:38:27
On the heating element itself.

The end of the wiring at the seat connection is pretty bombproof. The heater pad itself flexes and breaks. Shorts cause hot spots and the resistors fail.


The seat bases are the same for both front seats. Which means you can fit a passenger one to a driver's seat in a few minutes. They get a lot less use, so the heat pad is much more likely to work, the trim won't be as worn, and the foam will be in better condition.


This was one of the better things I did to my car.
So both front seats show infinity when measured from Black connector. So that is the way to measure it? No higher tech inside the seat?
Title: Re: Heated FL Front Seats Wiring & Control
Post by: Doctor Gollum on 19 January 2022, 17:50:37
I'll need to have a look at the diagrams. Shall report back... ;)
Title: Re: Heated FL Front Seats Wiring & Control
Post by: polilara on 19 January 2022, 17:58:31
I'll need to have a look at the diagrams. Shall report back... ;)

Good, thanks...
Title: Re: Heated FL Front Seats Wiring & Control
Post by: STEMO on 19 January 2022, 19:12:29
I have hotspots on my drivers seat too.  ;D
Matching stains too I shouldn't wonder ::)
I hope not  :(
Changing my front sear would cost more than your car did  ;D
Title: Re: Heated FL Front Seats Wiring & Control
Post by: LC0112G on 19 January 2022, 21:55:01
Hello, read here
https://www.omegaowners.com/forum/index.php?topic=149084.0
and other places too, that FL front seat "heaters aren't known for their durability"...
So mine are broken, too, 2001 FL (Elegance) Tried to check the wiring a bit...
So, five Connectors, below is what I think?
Yellow=Side Air Bag
White or Light Gray with Brown and Blue wires=Seat Belt Tensioner
Grey with Brown and Red=Electricity to Standard Seat up&down control motor
Green with Black having Yellow stripe and another Black having Green stripe indicates 11kOhm resistance. Is this the 'heating controller' unit (PTC/NTC) resistor TB discussed in link above? Temperature was +10 degrees Celsius.
Black with Black and Brown, resistance here is infinity so if this is the heater units (in series) one of them certainly broken.
If it is as described above:
1. What should be the resistance of the heater unit when ok?
2. How does the control work, is it On/Off according to temp measurement (1-5) or are there resistors somewhere which gives 5 different Voltages?
3. What is typical place to find failure if heater unit is broken?

Sadly, you can't test the seat heater elements like that. There is an electronic control unit in the seat itself - K183 and K184 in the circuit diagrams.

The thin Black/Yellow wire is the main on/off from the dashboard switch.
The Black/Green wire is an analogue resistance from the dashboard switch which presumably controls how hot the element gets.
The thick black wire is the Main Power (12V from fuse F15)
The thick Brown wire is Ground/Chassis/Earth/Whatever you want to call it.

There is one connection from K183/184 to the heater element +ve, and a ground (to the brown wire)
There is one connection from K183/184 to the thermistor, and a ground (to the brown wire)

So to test the element you're going to have to locate K183/184, and unplug them. I'd expect the element resistance to be less than a few ohms.

I suspect K183/184 may look like relays - the terminals on the circuit diagrams are labelled 15 (12 V from Fuse F15), 31 (ground), 86E (dash on/off), P (dash temperature control), T (Thermistor), H (Heat Pad)
Title: Re: Heated FL Front Seats Wiring & Control
Post by: polilara on 20 January 2022, 12:23:23
OK, thanks, seems more complicated than I thought. I try to look the schemes, too. I have Haynes 3510-352. If I take diagrams for later models from there maybe I find something there??
Title: Re: Heated FL Front Seats Wiring & Control
Post by: LC0112G on 20 January 2022, 13:20:22
OK, thanks, seems more complicated than I thought. I try to look the schemes, too. I have Haynes 3510-352. If I take diagrams for later models from there maybe I find something there??

The circuits in Haynes are for PFL cars. FL cars have significant wiring differences in some areas, and heated seats is one of them. You need this...

https://github.com/MalcolmRobb/OmegaBCircuits/raw/master/3700-3749.pdf

I assume you're in Finland and its a LHD car? Front seats are lines 3700-3731, and rear seats are 3732-3749.

E25/E30 are the heat pads, and P87/P90 are the thermistors. S30/S55 are the dashboard switches, and X36/X37 are the electrical plugs you've found (under the sill covers). What I can't find from the information to hand is where K183/184 are located or what they look like. My guess would be they're on the seat base somewhere, and look like relays - but tis only a guess.
Title: Re: Heated FL Front Seats Wiring & Control
Post by: polilara on 20 January 2022, 14:09:53
Thanks a lot, now it looks better five position switch etc, and relays having like "NPN transistor" symbol or do all relays have that in those drawings. Have to check, this is interesting!

Yes and LHD, we drive in the Right side, not wrong side.
Title: Re: Heated FL Front Seats Wiring & Control
Post by: LC0112G on 20 January 2022, 14:14:51
Thanks a lot, now it looks better five position switch etc, and relays having like "NPN transistor" symbol or do all relays have that in those drawings. Have to check, this is interesting!

I think the transistor symbol just implies there is some semiconductor switching logic in there - it's more than just a relay or mechanical switch.

Yes and LHD, we drive in the Right side, not wrong side.

Ahh, but our steering wheels are on the right side, whereas yours is on the wrong side  ;D