Heated Seats?!

[MIKe30]

k i was just going through my bmw manual cuz i was about to look up the fuse for the fuel pump so i can do my fuel filter change...

then it got me thinking...

is it possible/feasible (or feasable sp?)/difficult to make my 90 325i have heated seats?!

i have the sport seats with the wire thingy underneath, what would i need to do next?

sidenote: if all goes well (which i really hope it does) i will have an older eS to take any S package options that i want off of it and swap/put into mine... and right now i'm guessing that the heated seats is an S thing...


so... has anyone ever done it?

[kup325is]

I would also be interested in knowing this as my vader seats are heated in my 325is which doen't have heated seats originally.

[euro96]

who knows, the seats might already be wired up and you might just need a switch??

[Andrew546]

I think when I had my seat out, there was just a wire that was connected under the seat, and all you would need to do is plug something into it. I would love to have heated seats instead of sitting on cold vinyl in the winter.

[czag13]

You would have to run wires and find switches, don't really know much more than that. I just picked up a heated seat out of a cabrio and this was the wiring underneath the seat:

One is for the seat belt sensor (I think) and the other is for the heated seat. If you check realoem.com, you can see everything you need to retrofit heated seats into your car.

And from what i know, heated seats weren't an S thing.

[MIKe30]

hmmm so i guess if it wasnt an S thing it was just an option?

... interesting.




i do hope though that somebody posts thats done it before!!!

[Ablice]

Heated seats were a common option in Europe and Canada, but not to a great extent USA and the UK, and they were a option for most cars, but whether or not it was an iS wasn't the defining factor.

Air conditioning, on the other hand was mostly found on USA cars and South African carriages, but rare on Euro cars. It was a £1376 option back in the heydays of the E30s for UK cars in 1990, that translates to...almost $3900 in todays dollars, adjusted for inflation.

Basically to fit heated seats first you need the proper working seats. Then you pull up the carpet entirely. Then you hook it up under the glove box or the driver's under-dash panel. (RHD, LHD respectively) You then hook up the ground to the nearby earth point, plugin the fuse and the switches.

Lot'sa fun.

[czag13]

found this

[MIKe30]

some good info... good stuff...

[euro96]

heated seats were the only option offered on the 1990 325is...i can prove that because i have my original sticker from 1990

[87Blue325iC]

You need the heating elements (2 per seat), the wiring harness, the switches (2), and the new relay, plus the harness holder.

For the coupe sport seats, you need to actually cut slits into the leather to fit the heating elements. The cabrio and M3 seats are much easier - as you can just slide in the elements from the side. I retro-fitted heated seats into my cabrio and love them. Not an easy job, and you will be completly disassembling your seats in the process + taking everything out of the inside of your car to be able to lift up the carpet to get the wiring harness run to the right places.

If you can find some seats that already have working heating elements in them, you would be much better off. Then you just have to source the wiring harness - when I bought mine it was the last one shown in stock in the USA per the dealer.

[MIKe30]

so what does the wire/plug thingy underneath my seat do then? it connects to a wire that was hanging out of the floor if i'm not mistaken but i dont ever remember anything about seat belt warnings or anything like that... and i'm 99.99999999% sure i dont have the heated seat option becuase there arent any "warm-the-seat-up" buttons by my e-brake.

[87Blue325iC]

so what does the wire/plug thingy underneath my seat do then? it connects to a wire that was hanging out of the floor if i'm not mistaken but i dont ever remember anything about seat belt warnings or anything like that... and i'm 99.99999999% sure i dont have the heated seat option becuase there arent any "warm-the-seat-up" buttons by my e-brake.

It is the seat belt warning chime sensor. There is probably no similar wire/plug under your passenger seat, correct?

You would have two plugs if you had heated seats - one for the seat belt sensor and one for the heated seats. Passenger side would only have the heated seats plug.

[mmirE30]

Anyone know which relay the new one replaces?

Also, is there a power seats retrofit diy available?

[ThomHart]

Have a DIY retrofit in progress. All four of my seat heater elements were bad and rather than buy $400 worth of OEM replacements I got the Innovative II kits from heatedseatkits.com for $130. I usually put only BMW parts in my cars but I had used the Innovative II kit on my Landcruiser and if was far superior to the old technology on the '88 325iC I have. It is a work in progress and I'll post how I wired it in and installed the elements in the seats when i get it working.

[02rollin]

my low setting on the drivers side seat is not working (the light also does not go on if i put it on "low"

Is there a way to fix this or check it witout out oulling the whole seat out and checking every connection?

[richardodn]

my low setting on the drivers side seat is not working (the light also does not go on if i put it on "low"

Is there a way to fix this or check it witout out oulling the whole seat out and checking every connection?

Your seat has 2 elements, base and back. In low they are connected in series and in high they are connected in parallel. Do the base and back work in high setting?

Anyone know which relay the new one replaces?

Also, is there a power seats retrofit diy available?

The relay is not used. Power comes from fuse 16 (which may need to be added) down to the accessory power connector at position "U". This part should be prewired.

The seat heater harness plugs in there and runs under the carpet to the console for the switches and under each seat for the heater elements.

You have to make some cutouts in the console for the switches or get the console section from a donor car.

[02rollin]

Your seat has 2 elements, base and back. In low they are connected in series and in high they are connected in parallel. Do the base and back work in high setting?

oh ok, but yes both seat and back work on high setting. Maybe that means somehow the series connection is disconnected??

[montrealmike]

Like all the new info I have gained in this post!

Thanks for everyone who commented

[richardodn]

oh ok, but yes both seat and back work on high setting. Maybe that means somehow the series connection is disconnected??

It's all handled in the switch. sounds like the switch is bad. Try swapping them and see if the problem follows the switch.

[Rubbie]

oh ok, but yes both seat and back work on high setting. Maybe that means somehow the series connection is disconnected??

On the high setting only my seat back element works and it doesn't feel like either works on low.
would a simple switch swap solve this issue or do i need to dig around in my seat for a broken wire?

[richardodn]

It's possible there is a broken wire but more likely the element is bad. What happens in the low setting?

[Rubbie]

It feels like nothing happens on the low setting. Ill let the element heat up with the high setting, then switch it to low to keep my back nice and toasty and it feels like it just shuts off.

It could just be that my back isnt sensitive enough to the heat but the low setting isn't noticible compared to the firey hotness that is high

[richardodn]

No in low the elements are wired in series. It sounds like the seat bottom element is dead. You may want to remove the seat and check for a bad wire but it's probably the element itself.

[Rubbie]

Will do

Thanks for the help