Z4 Heated Seat Wiring loom (Retro - Fit Kit)
- Thread starter Darkangelv2
- Start date
thanks for the heads up.That's good news. Mine arrived in a few days and were genuine BMW parts. Remember when making your connection to the switch panel that the wiring instructions are for a left hand drive car. Both Marlon's and mine ended up the wrong way round and had to be changed. Not a big problem but hopefully a heads up will save you doing the same thing. Good luck.
Reviving an old thread... I've trawled to the end of the internet and I've not been able to find anyone selling the retrofit cable (61110307620).
Anyone else had any luck recently?
If it really is no longer available, would it be possible to use a generic heated seat retrofit kit to connect and work with the OEM Z4 heated seat switches ? i.e. do the Z4 switches somehow alter the resistance in the circuit to control heat, or is it all done through the magic of CANBUS ?
Anyone else had any luck recently?
If it really is no longer available, would it be possible to use a generic heated seat retrofit kit to connect and work with the OEM Z4 heated seat switches ? i.e. do the Z4 switches somehow alter the resistance in the circuit to control heat, or is it all done through the magic of CANBUS ?
Zulu4 said:
I’ve done the same with the same (negative) result
If you don’t have electric seats though, the heated part is controlled through PWM from one of the body control units (I forget which one) which makes me think I could get a generic set work as they too tend to work with PWM to regulate the different settings.
ProfCJJ said:Zulu4 said:
I’ve done the same with the same (negative) result
If you don’t have electric seats though, the heated part is controlled through PWM from one of the body control units (I forget which one) which makes me think I could get a generic set work as they too tend to work with PWM to regulate the different settings.
Please keep us updated if you do manage it Christopher.
I wonder if a generic kit with a three-position heat switch, you could just cut this off and wire up to the OEM switch ?
(I have the 2007 E85 model with electric memory seats)
Kendodeal83
Member
Yes please keep me updated I’m trying to get a loom but it’s a bit of a minefield to know exactly what is required think I may call bmw but they are pretty useless wen it comes to things like this
Interesting read. Thanks.clarker63 said:I dont know about the e85/6 but on the e89 I made the cable, its not that hard, which uses the PWM from the JBBF module (which needs coding). its in here if that helps. I assume there's some similarities
https://z4-forum.com/forum/viewtopic.php?p=1363305
Where did you get the correct size connectors from to make up the cables so that they fit into the existing plugs ?
Ah, thanks missed that bit.
If I understand you correctly, the variable heat to the mats is controlled by a pulse width modulation of current (via 12v voltage). I'm guessing that the heated seat switch in the car is just providing its position in binary form to a processor, which then switches a small power transistor on and off for the PWM. Am I along the right tracks ?
So, if I could get a generic kit with a 3 position switch (similar to that fitted in an E85), I might be able to fit the kit to the BMW OEM switch instead. Any thoughts on this idea?
If I understand you correctly, the variable heat to the mats is controlled by a pulse width modulation of current (via 12v voltage). I'm guessing that the heated seat switch in the car is just providing its position in binary form to a processor, which then switches a small power transistor on and off for the PWM. Am I along the right tracks ?
So, if I could get a generic kit with a 3 position switch (similar to that fitted in an E85), I might be able to fit the kit to the BMW OEM switch instead. Any thoughts on this idea?
Kendodeal83
Member
Zulu4 said:
I believe that a lot of aftermarket kits with more than one setting use PWM too - meaning that it should be a direct swap. I have yet to buy an aftermarket kit to prove this though.
PWM - or pulse width modulation is a way of simulating different analogue voltage levels through manipulation of a digital signal. The heated seat line is pulsed between 0V and 12V. For full power the pulse is almost always at 12V meaning that the average voltage level will be high. At the lowest setting the line will be pulsed so the line spends less time at 12V and more time at 0V. So by pulsing a line between 0V and 12V it’s possible to create an output at different voltage levels and thus different heating levels. It’s a bit of a “poor man’s” way of doing it though which is why it’s only done this way using the JB electronics module if you don’t have the full electric seats module - which needs a CAN bus connection.
HTH