BMW power seat wiring info needed

[dpr64]

Working on a BMW power seat install with the Torfab brackets and was wondering what the general consensus was on what size AWG wire to use for the large power/ground wires that you need to hook up to on the seats? I think I read they are set up to need a 30amp connection per seat or am I crazy?
Also, where are people running the power lead to? Fuse box/battery/or ? Good to run an inline fuse or ? For the ground, I am assuming just run an eyelet and bolt it to the body under the carpet or is that a no-no?
I am a good carpenter but know squat about electrical!

 

[86aggie]

Here is a link to a site that you can track down the exact pin out for your seats.

newTIS

That will take you to mine, from a 2008 335i. Go to the home page and find your donor vehicle. The diagrams will also give you the amps for each circuit.

I have a panel that replaced my fusible links, with MIDI fuses. I came off of that to a Blue Sea fuse box with six fuses. Only used 4(2 for each seat). Used radio illumination wire for heater switches. You will want to put an inline switch on the driver's power wire. See LCnAZ's build thread for what he used and where he installed it. Any ground location is fine, just make sure it is clean and solid.

 

[dpr64]

Oh damn, that is too deep for me! Here is mine, can you tell me the amps need for each seat?

newTIS

 

[86aggie]

They are both 30 amp. You may want to figure out the wiring diagrams, and how to read them, to make sure you are making the correct connections at the plugs.

 

[dpr64]

They are both 30 amp. You may want to figure out the wiring diagrams, and how to read them, to make sure you are making the correct connections at the plugs.

All of the wires are moot for me aside from the power/ground which are the large orange -ish red and brown, both large wires perhaps 10 to 14 gauge?

 

[86aggie]

Power should be brown with a red stripe and ground should be all brown. Both are same size, 2.5mm. Not sure what gauge that is. I used 12 gauge. Ground goes to pin 6 and power goes to pin 8. Bottom row(wider) is pins 1-8, top row is 9-15.

 

[dpr64]

Huh?? Power is pin 13 and red and ground is pin 13 and brown...

 

[dpr64]

I jumped them today off a battery and had full motion function along with the lumbar working.. (not interested in heat and or memory)

 

[dpr64]

I know 'what to hook up' but want to know where to terminate the connection, fuse box, battery, etc.. and what gauge or awg wire size to use... Should be simple??

 

[86aggie]

Sorry, I was looking at the connection at the control box.

Install an inline fuse and wire, closer to battery(under hood), for each seat. 12 gauge. If your driver seat controls time out(stop working) after a few minutes, then install a switch at seat base(double sided tape to frame), to cut power on and off. When you do that, the controls will come back. It will only happen with Driver module, not passenger, if it does happen.

 

[dpr64]

So 2 actual wires to the battery, not 2 into one? (Use one seat at a time?). Also, can I run the ground to a bolt fastened to the floor area somewhere under the seats?

 

[LCnAZ]

You are asking for standard answers to non-standard questions. It's counter-intuitive to logic. IF you want to take the risk of never using the two seats simultaneously, go for it all on one. Most of us would never do that. Man up on your sweat equity time investment and run two 12AWG runs to the battery, each with a 30 amp fuse...then enjoy with peace of mind...and ours.

 

[86aggie]

Some of the electrical experts can weigh in on the 1 vs 2 wire, however, in my opinion, given the size of the circuit, better to have one fused line for each seat. Consider it cheap insurance on multiple fronts. Come thru the rubber grommet for the AC drain line in the firewall in upper left passenger footwell.

 

[dpr64]

You are asking for standard answers to non-standard questions. It's counter-intuitive to logic. IF you want to take the risk of never using the two seats simultaneously, go for it all on one. Most of us would never do that. Man up on your sweat equity time investment and run two 12AWG runs to the battery, each with a 30 amp fuse...then enjoy with peace of mind...and ours.

But..but.. I can save .75 on only using half the material!!!
How about the ground? Any good steel body point under the seating area/console area fine?

 

[86aggie]

Any ground connection is fine, as long as it is clean and solid.

 

[LCnAZ]

But..but.. I can save .75 on only using half the material!!!
How about the ground? Any good steel body point under the seating area/console area fine?

If you are looking at the original BMW wires, take your cue from their guage. The brown ground is also 12 AWG IIRC.