Aftermarket heated seats with factory buttons

[subieworx]

Recently changed my wife's car from an e92 335 to e53 x5 sport. So far she loves it but the one thing it is missing is heated seats.

I know most people will tell me to get heated oem seats and install them but I don't feel like paying $1000 for seats right now. Others will tell me to install an aftermarket kit which I am fine with but she really wants the stock buttons.

It seems to me that there would be heated seat wiring already run to the seat area for an easy retrofit by the factory when a car with heated seats is ordered. I haven't specifically looked for this wiring but have seen it for the rear heated seat option.

I have also looked on realoem.com for the heat pads from BMW but they don't seem to exist outside of the full seat assembly. I have no problems taking the seats apart to install the pads and have no problem doing light wiring. If someone can point me to part numbers for oem heat pads and wiring I would be all over it.

Beyond that has anyone tried to use e oem buttons to control aftermarket heated seat pads?

[Turbo_Bimmer]

Heat pads alone don't exist for the X5.
But they do exist for the E30. I don't know if they can be retrofitted to the X5 though.
Look here:
RealOEM.com * BMW E30 318i Seat heating

[Skyline]

Originally Posted by Turbo_Bimmer

Heat pads alone don't exist for the X5.
But they do exist for the E30. I don't know if they can be retrofitted to the X5 though.
Look here:
RealOEM.com * BMW E30 318i Seat heating

I'm pretty sure you can add butt-warmers to anything. My local custom stereo shop sells generic kits. Back warmers too. Using the factory button should be easy too. Using the factory wiring? That sounds like more trouble than it's worth.

[TerminatorX5]

the buttons for the front heated seats are part of the module A169, they are not dry contacts, they generate signal for the system to turn on the pads, and even if the green lights are on on the buttons, and the voltage is below a threshhold, the pads will not heat up...

[TerminatorX5]

Seat heating

The seat heating system heats the seat cushion area and backrest. The electronics for controlling the selected heating temperature (3 stages) and fault monitoring are integrated in the switch centre of the centre console.
Function

Seat heating can be switched on in three heating stages as from terminal 15 by pressing the button. Three LEDs built into the switch centre light to indicate operation. "Terminal 15 active" is signalled to the centre console switch centre via the K-bus.
Initially, heating stage 1 is activated when the seat heating is switched on (button pressed once). The seat surface is heated up to approx. 44 °C. All three LEDs light to indicate operation.
By pressing the button once more, the topmost LED goes out and heating stage 2 is activated. The seat is now only heated up to 39 °C.
The seat heating system is switched to heating stage 3 by pressing the button once again. The bottom-most LED lights. The seat is heated up to 35 °C.
The seat heating is switched off by pressing the button once again or switching off the ignition. The seat heating can also be switched off in any heating stage by pressing the push button for longer than 1 second.
The seats are heated by means of carbon fibre heating mats in the main section and steel wires (steel filaments) in the bolster. A carbon fibre heating mat is installed in both the seat cushion section as well as in the backrest. The centre sections of the seat and backrest as well as the bolsters of the seat and backrest are always heated. Heating filaments or carbon fibre mats are additionally integrated in the thigh support on sports seats. The seat and backrest bolsters are not heated on the series E39 sports seat with fabric cover.
The temperature is measured by a temperature sensor in the seat upholstery and passed on to switch centre.
Monitoring functions

Battery voltage

The electronic seat heating control switches off the power supply to the heating mats if the battery voltage in the vehicle is less than 11.4 V ±0.3 V. The function LEDs however remain on. Power supply to the heating mats is restored when the battery voltage is greater than 12.2 V ±0.3 V for at least 5 seconds.
PC-Board temperature

Due to the fact that the power input of the seat heating system is very high (120 W), the temperature of the pc-board in the switch centre is monitored by temperature sensors. Initially, the heating power is reduced as the temperature increases to over 85 °C. The heating is switched off if the pc-board temperature exceeds 95 °C. The function LEDs however remain on. The seat heating cuts in automatically again when the pc-board temperature drops below 85 °C.
Fault monitoring

The electronic seat heating control system monitors the temperature sensor and heating mats for faults. Detected faults are stored in the fault code memory of the centre console switch centre.

The following faults can be recognized:

• Short-circuit or line break
• Short-circuit or line break of temperature sensors
• Break in heating mats

If a break or short occurs at the temperature sensor, the seat heating is switched off in order to prevent overheating. The function LEDs are switched off.

[JCL]

See this thread for photos and wiring instructions. It is talking mainly about the rear seats but there is a lot of good info.

Switches can be used, wiring exists, relay slot will be empty, aftermarket pads may have a different wiring scheme for multiple heat levels.

http://www.xoutpost.com/bmw-sav-foru...-pictures.html

[TerminatorX5]

this passage is from a factory HID retrofit on E53, but I thought it might be of interest - i have printed a screenshot, as original BMW files will not let me copy and paste or print... I read the passage but I still do not understand - if a car is equipped with certain options, some other options become prewired, as the factory is using only 4-5 main wiring harnesses... or, I am wrong?

[subieworx]

Those links were helpful.

Interestingly enough it seems the individual parts are available for the x3 and some sites cross reference them to the x5.

RealOEM.com * BMW F25 X3 28iX Electric parts for seat heating