Thank you 
Heating BMW seats (using BMW parts)
- Thread starter red66toy
- Start date
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- Thread starter
- #22
Finally got the seats all hooked up and they seem to be working. What seat temps are other people getting at the seats? My seats started out at 46 degrees and rose to about 70-80 degrees in about 6 minutes. Seems a bit low but I have no idea what the programed temp is so maybe that is normal?
Sounds about normal. I just tested mine for reference.
After a 15 minute drive with my seat heater set to the highest setting, I was getting high 80s on the surface.
It felt pretty comparable to the highest setting in my other vehicle.
Hope this helps.
After a 15 minute drive with my seat heater set to the highest setting, I was getting high 80s on the surface.
It felt pretty comparable to the highest setting in my other vehicle.
Hope this helps.
- Thread starter
- #24
Super helpful! Thank you for that. Good to know mine are functioning as they should.
- Thread starter
- #25
So I ended up switching out the original BMW switches with this different style BMW switch. I like the two settings. The hot setting is "taint tickling good" and heated up fast! I love this upgrade so much. Now if only I could afford heated AND cooled seats, that would be the real bee's knees in these green house cruisers. hahaha
Smooth!! Did they wire up any different than the other ones?So I ended up switching out the original BMW switches with this different style BMW switch. I like the two settings. The hot setting is "taint tickling good" and heated up fast! I love this upgrade so much. Now if only I could afford heated AND cooled seats, that would be the real bee's knees in these green house cruisers. hahaha
Been looking for a simpler way to hook up mine. It as off-low-high?
- Thread starter
- #27
Both switches share the same plug on the back so its a quick swap!
Yeah, its high, low and off. And fully illuminate at night as well.
Both switches share the same plug on the back so its a quick swap!
Thanks for the Intel!
I really need to do this, just need to find a good source for the parts. Ordering on ebay to Norway usually ends up lost in transit or a spread delivery over 2-7 months.
If anyone comes across a good dealer, I'll be happy to double the order up.
P
Hey OP question since I'm trying to do something very similar. I need the larger flat-blade pins for (the Male for #24 and #25) but you list 61138364834KT - that's the female ends (according to ECS tuning)
What is the part number for the male ends you're using? I need those exact pins for my heated seat project
What is the part number for the male ends you're using? I need those exact pins for my heated seat project
- Thread starter
- #30
Sorry I dont have those part numbers.Hey OP question since I'm trying to do something very similar. I need the larger flat-blade pins for (the Male for #24 and #25) but you list 61138364834KT - that's the female ends (according to ECS tuning)
What is the part number for the male ends you're using? I need those exact pins for my heated seat project
Mine were already in place so I didnt hunt them down. If you find them please post them here! I can try and look later as well.86aggie
SILVER Star
try waytek
These are specific BMW pins. I believe the PN is 61138364835 and 61138364833 (the differences depend on how thick of wire you want to crimp). Just ordered a few so I will report back.
- Thread starter
- #33
Awesome!
Hi @red66toy ! I just wanted to say thank you for creating and following up on this thread. I've been trying to retrofit a pair of E9x BMW heated seats for a couple of weeks and have been trying to determine what is the right switch to use. Thanks to you,, I will go with the E36 switches like yours.
One thing I cannot figure out is if the E9x seats have a negative thermal coefficient (NTC) signal wire; I've attached a wiring diagram I found online. Of the 13 terminals on the right hand side, I know I will be using the following:
2 - CANBUS H (will be using 12 to 5V pulse generator)
3 - CANBUS L
4 - 12V power
7 - 12V power
8 - ground
13 - ground
Which leaves 1 and 5... I can't tell from their descriptions if they are the NTC or not... any advice on this?
One thing I cannot figure out is if the E9x seats have a negative thermal coefficient (NTC) signal wire; I've attached a wiring diagram I found online. Of the 13 terminals on the right hand side, I know I will be using the following:
2 - CANBUS H (will be using 12 to 5V pulse generator)
3 - CANBUS L
4 - 12V power
7 - 12V power
8 - ground
13 - ground
Which leaves 1 and 5... I can't tell from their descriptions if they are the NTC or not... any advice on this?
- Thread starter
- #35
Hopefully someone with E90 seats can chime in but I believe some others have bypassed the canbus system somehow. I’m not terribly familiar with the E90 seats. They may have the NTC sensor/switch built into the seat , and not in the switch like the older generation seats like I have.
#1 is correct if you have the seat heater module under the seat.
I bypassed the module and wired directly to the heater elements. I’m using the 80 series heated seat switches that are two level (hi/low) and use a relay to flip the heater elements between series and parallel. I’m not planning to use the thermistor wire.
According to this video: ... (skip to 25:15 for CAN explanation)
You can mimic CAN H by using a pulse generator or a step down so that the computer receives a constant signal to stay "awake".
CAN L is just ground.
Awesome, thanks for the confirmation! My seats should be fully powered and heated.
Can you clarify what you mean by using a relay to flip the heater elements between series and parallel?
And if you are not planning to use the thermistor wire, do you just turn off the heat when it gets, "too hot" ?
Side questions:
1. If there is no NTC or thermistor to automatically turn off the heating elements, how hot can these get? I assume the fuse will blow to prevent any serious damage.
2. Does anyone what are the maximum temperatures the seats reach when there is a "high" and "low" switch?
I should be finishing up my brackets this week and hope to install by end of next week.
Thanks for the responses, guys!
Ohhh okay, I think I understand now. Thanks for the picture!
Wow this is amazing to see that you came back 5 years later and updated this thread!!
Lots of good info in this thread!
I'm trying to get the heated seats turn on when I remote start my E39 528i 1998
I have the same switch with a roller wheel to adjust the heat strength.
I also only have 5 wires at the switch like another poster, not 6. But my seats are heated as well as backrests.
I did some poking with the multimeter.
With car running, started from the key in ignition, I get 12 volts on pin 3.
If I press the button for heated seats, I get 12 volts on pin 5. So I thought all I need is power on pin 5 to heat the seats?
Now what's really weird...if I remote start the car, pin 3 will have no power, but pin 1, which is switch illumination, will for some reason have 12 volts instead of pin 3. Yet the button is NOT lit.
I wired in a relay the following way.
Terminal 85 is grounded by a negative 250mA from the remote module.
The main power on terminal 30 is provided by the remote module output second ignition wire.
Now I used wire from pin 1 on the heated seat switch for terminal 86 on the relay.
So when I start the car, remote module provides constant power to terminal 30.
Negative output from remote module to terminal 85 and positive from wire on pin 1 of the heated seats energize the relay, and power from terminal 30 flow to terminal 87, which is connected to wire on pin 5 of the switch.
I double checked by starting the car this way that wire going to pin 5 on the heated seat switch has 12 volts.
My understanding is that the seat should start heating up but for some reason it doesn't.
Now I have 3 questions as a result.
- Why do I have 12 volts on pin 1 of the switch if I start the car remotely, and nothing on pin 3. However if I start the car with a key, it's the opposite (pin 3 has 12 volts and pin 1 has 0)
- Why are the seats not heating with my setup, I.e. power going to wire 5 of the heating switch.
- Should I just drop the relay and connect the power wire out of the remote starter directly to the wire on pin 5 of the heated seat switch?
Lots of good info in this thread!
I'm trying to get the heated seats turn on when I remote start my E39 528i 1998
I have the same switch with a roller wheel to adjust the heat strength.
I also only have 5 wires at the switch like another poster, not 6. But my seats are heated as well as backrests.
I did some poking with the multimeter.
With car running, started from the key in ignition, I get 12 volts on pin 3.
If I press the button for heated seats, I get 12 volts on pin 5. So I thought all I need is power on pin 5 to heat the seats?
Now what's really weird...if I remote start the car, pin 3 will have no power, but pin 1, which is switch illumination, will for some reason have 12 volts instead of pin 3. Yet the button is NOT lit.
I wired in a relay the following way.
Terminal 85 is grounded by a negative 250mA from the remote module.
The main power on terminal 30 is provided by the remote module output second ignition wire.
Now I used wire from pin 1 on the heated seat switch for terminal 86 on the relay.
So when I start the car, remote module provides constant power to terminal 30.
Negative output from remote module to terminal 85 and positive from wire on pin 1 of the heated seats energize the relay, and power from terminal 30 flow to terminal 87, which is connected to wire on pin 5 of the switch.
I double checked by starting the car this way that wire going to pin 5 on the heated seat switch has 12 volts.
My understanding is that the seat should start heating up but for some reason it doesn't.
Now I have 3 questions as a result.
- Why do I have 12 volts on pin 1 of the switch if I start the car remotely, and nothing on pin 3. However if I start the car with a key, it's the opposite (pin 3 has 12 volts and pin 1 has 0)
- Why are the seats not heating with my setup, I.e. power going to wire 5 of the heating switch.
- Should I just drop the relay and connect the power wire out of the remote starter directly to the wire on pin 5 of the heated seat switch?