Sorry everyone got side tracked.. things that through me off 1.. bmw schematic is actually backwards.. the one you pointed to helmuth is actually backward on wds bmw reversed the wire code up on that page. you have to look up this schematic x337 that actually is the rigth schematic for the wiring. 2. monday driving home caught a flat tire. had to put everything back together so bmw would replace it under warranty. 3 my seat heat elements are 2 wires they are wired in series where as bmw uses there in parrallel and use 3 wire. Still trying to source the thermistor on digikey and mouser website so I can add it to the circuit. My elements do have temp switch tested it out today with a heat gun and it went from 2.3 ohms to 0/infininty.
4. its freaking cold..lol. in my searching I found some good info.
seat heat temperatures
NTC thermistors
3 stage switch for front seats but im doing the rear and they are set by bmw for
2 stage switch.
stage 1 high = 44ºc
stage 2 med = 39ºc
stage 3 low = 35ºc
input = 120w
95ºc turns off
so this is what i think i need from mouser or digikey 2 NTC thermistors 1 for each side. I guess
at 10kΩ and operating temp of 40º C and 120w with 10 amp current not sure if
they will work any electronics engineers? Im working the circuit over with my dad in his spare time.. I do not feel like buying new aftermarket elements.
also found some good info here about range rovers which were i think made by bmw.
Heated Seat Temperature Upgrade on Range Rover 4.0/4.6
i did finish the retrofit of the rear footwell lights that was done in under 30 mins.