new bmw seats now what to do with all these wires?

[dozerking]

So this weekend i got some heated seats out of a 2001 325 bmw four door car. Im not real sure what all the wires are for? The two big brown wires are ground and the big red wire is power! I have the power to the seats so they move back and forth but i have no clue what i need to do to wire in the heated seats!!


1 I never got the switches what will be the best kind to use?

2 How do i wire them when i do get them?

3 how many volts run to the heating elements? do i need to use a resistor and relay?


Thanks for any help!!

 

[TS888]

The heaters will draw 12 volts... It's the amps that are the issue. Probably 10-15 amps per seat. For that you will need relays, and fuses.

Are the heat elements single or two stage (i.e. low and high heat)? Also, are there timers on the heaters? What wiring is present inside the seat? It would not be unusual for the relays and fuses to be in the seat base, so all you would need to do is wire up switches and power to the relays.

Assuming the seats are not carrying the goodies -- If they are single stage, then you just need an SPST switch, a fuse and a relay for each seat. If they are two stage, the wiring get a bit more complicated if you want both temperatures.

Wire up the relay main power (30 terminal) through a 15a fuse and feed the 87 terminal to the heat element. Wire 12v to the switch and on to the 85 terminal, and ground the 86 terminal.

For the seat movement motors, you need a DPDT switch for each motor. You get the motion/reverse motion by reversing the polarity of the power feed to the motor.

 

[dozerking]

thanks for the reply! Here a few more pics of the bottom of the seat and the side the buttons to move the seats back and forth are already on the seats and i have them powered up and working! They are a two stage with a low and high.
I have the main plug in that goes into the seat that was the first pictures im thinking one wire is for high on the back rest one for high on the lower part and the same for low. that leaves four more small wires im pretty sure the two wound around each other are for some kind of airbag? the other two i think go to the seatbelt switch? and the big green one i have no clue!

im not sure what you mean when you say 30,87,85 and 86 terminal??

 

[DPIN]

Just wondering... Are you making your own seat brackets?
Tks

 

[TS888]

The numbers I listed refer to the terminals on a standard 4 terminal bosch style relay.

That black plastic box with the blue lettering is probably related to the heating. The silver label on the wire may have a part number to check.

You could probably do some fishing on a BMW forum and get some help with the wire colors.

 

[Pacer]

Nice mod!
Are they bolted in yet?
Good height?

 

[dozerking]

yes i making my own brackets these bmw seat have a flat bracket and are about two inches wider and 3 inches longer ill post some pics of the second braket i have one seat in now and they do sit pretty high!! im 6'2 and with the seat lowered all the way its as high as i would want want it if your short they go up about 4 inches higher! very comfy though!

 

[dozerking]

The numbers I listed refer to the terminals on a standard 4 terminal bosch style relay.

That black plastic box with the blue lettering is probably related to the heating. The silver label on the wire may have a part number to check.

You could probably do some fishing on a BMW forum and get some help with the wire colors.

Alright i got ya now! should i run the relay before or after the switch? does the switch adjust the amperage or do i ned something for that as well? I did get on a couple of bmw forums but they have nothing for what the wires do if they switch new seats into an old car i guess they have different plug ins that work for everything so they dont have to cut any wires! i might have to try to find a fsm!!

 

[alpinemechanic]

The black box is a control unit for the occupancy mat, I worked on spammers at BMW for a long time!!! Sounds like you have worked out the rest

 

[alpinemechanic]

Ha! I ment spanners not spammers

 

[rcmccars]

google gave me this http://www.bimmerfest.com/forums/showthread.php?t=629522
be carfull of that airbag they hurt and mess up the seat. i wouldent do anything till i make 100percent sure i know what wires go to it.

 

[alpinemechanic]

The original car had what they call logic switches which work on around 5v. The switches would send a signal to a small computer. More like a keyboard to a computer rather than traditional car wiring. Your best bet would be to the control unit for the seats if u want all the features. Good luck cause they're complex enough when in the car they were designed for!

 

[ashack2004]

Nice Seats

 

[dozerking]

The original car had what they call logic switches which work on around 5v. The switches would send a signal to a small computer. More like a keyboard to a computer rather than traditional car wiring. Your best bet would be to the control unit for the seats if u want all the features. Good luck cause they're complex enough when in the car they were designed for!

alright so if you where in my shoes and you have an fj60 and you just got these bmw seats what would your actions be????
And what the heck is occupancy mat??

 

[tclark]

Best option :

 

[alpinemechanic]

The occupancy mat is a mat under the seat leather which tells the airbag control unit weather the seat is occupied. What exactly do you want to work? Is the control unit behind the switch panel?

 

[alpinemechanic]

P.s firstly I would remove the seat backing and check the car came with no airbag in the lumbar. If so preceded with caution, and remove by uncliping and peeling back the leather

 

[dozerking]

what i want to work is the power to slide the seats back and forth which i have done already the only other thing is heating the seats!! i dont have a control unit all i have for wiring right now is the plug in that goes into the seats and thats it! what king of switch can i use does it have to be a bmw or anything will work? what do i need for a thermo control unit so my seats dont melt down??

 

[alpinemechanic]

You should be able to use any switch, use a relay, I would have to probe wires/strip seat to find out what wires control the heating. Prob would recommend a rheostat/ variable resistor switch so u could control the voltage and temp?

 

[pandasfj]

it so happens that i just installed the same seats but with out the heaters. i plan on redoing the upholstery and installing after market heaters,i might even consider using the bmw heater n heater switch,if i can find the factory wiring diagram,still searching. you will have to somehow trace the heater wires and wire in the switch n fuse.