$28 seat heat pad replacement DIY

[Ctsiegf]

TB, when you had your seat covers apart, were the elements sewn into the seams where the hog rings go? Or can they be removed freely?

I made the mistake of kneeling on my seats last fall and broke the thermistor wiring. It worked intermittently for a while but finally gave up the ghost and won't stay on when the button is pushed.

There's a seller on German ebay that sells the elements by themselves but if i have to totally take apart the seams then it probably wouldn't be worth it to use those.

Otherwise it looks like a new skin will be on order before next winter (brrr). That or get another used seat to replace the bottom. This is my second pair of x5 seats since my e53 didn't come with heated seats originally.

Thanks,

Carter

[Turbo_Bimmer]

Thanks guys for the positive comments.
I did calculate for 13.8V, but at first I wanted a faster heating than what I had, that's the reason of the lower value resistor. But, yes, someone can increase the value to have a heating speed more like OE.

The mat came with hog ring pliers so I thought I was all set. But at the first use they broke (tin can metal...) and I had to finish the job so I went with two pairs of longnose pliers.

FWIW, My repair is still fully functional after 2 winters.

[Turbo_Bimmer]

TB, when you had your seat covers apart, were the elements sewn into the seams where the hog rings go? Or can they be removed freely?

Yes the elements go over the seams and into the side bolsters, but the hog rings are not attached to the mat, but to a long metal rod that goes front to back and under the element. So, once the hog rings are spread open, you just rotate them to remove them from the metal rod

I made the mistake of kneeling on my seats last fall and broke the thermistor wiring. It worked intermittently for a while but finally gave up the ghost and won't stay on when the button is pushed.
I did the same mistake and that broke the element wiring. Are you sure that in your case it is the thermistor wire and not the element wiring that are damaged? You can use a ohmmeter to verify.

There's a seller on German ebay that sells the elements by themselves but if i have to totally take apart the seams then it probably wouldn't be worth it to use those.
That would be even a bigger job, removing the heating mat from the leather skin. But I guess that everything is possible with patience.

Otherwise it looks like a new skin will be on order before next winter (brrr). That or get another used seat to replace the bottom. This is my second pair of x5 seats since my e53 didn't come with heated seats originally.
If your thermistor is still good, you could go with this $28 heating mat, or maybe I missed something in your explanation?

Thanks,

Carter

You're welcome,
Michel.

[jeepo23]

This thread is excellent, exactly the issue I ran into with my E46 drivers seat.

I am wondering, do you know if this can be achieved with any kind of mat? I've found some on ebay for $30,

2 Pcs Seat Heater Pads Heated Seat Pads Universal Carbon Fiber Seat Heater Pads | eBay

However, am I reading that correctly that these pads are only rated at 30W, while the one you bought is 100W and the BMW's are 50W?

And I am also wondering, how does the wiring work considering these pads only have 2 wires coming off them?

I did a fair bit of testing on my drivers seat, and it appears that if I apply pressure on the lower pad by the seatbelt buckle I can get the LEDs to stay on.. However I am not sure if this a issue with my heating grid or the temp sensor in the seat.

[Turbo_Bimmer]

Originally Posted by jeepo23

This thread is excellent, exactly the issue I ran into with my E46 drivers seat.

I am wondering, do you know if this can be achieved with any kind of mat? I've found some on ebay for $30,

2 Pcs Seat Heater Pads Heated Seat Pads Universal Carbon Fiber Seat Heater Pads | eBay

However, am I reading that correctly that these pads are only rated at 30W, while the one you bought is 100W and the BMW's are 50W?

And I am also wondering, how does the wiring work considering these pads only have 2 wires coming off them?

I did a fair bit of testing on my drivers seat, and it appears that if I apply pressure on the lower pad by the seatbelt buckle I can get the LEDs to stay on.. However I am not sure if this a issue with my heating grid or the temp sensor in the seat.

Thank you, I hope it can help you find a solution for your defective heating seat.
I think that other kind of mats would work also. The one I found was higher wattage, so I had to use a resistor to drop the voltage. If you can find one with the same power as BMW and a dimension that fits in between the side bolsters, I think you will be ok.
I wouldn't use one with a wattage lower than the BMW one though.

For the wiring, if there is only 2 wires, that means they are for the heating element. The extra wires on other models usually are for the temperature sensor.

By pressing on your seat you can make it work because you make the broken wires to touch each other and complete the circuit. The control module then sees a working mat and applies voltage.

[stackz]

Originally Posted by Turbo_Bimmer

A pair of hog ring pliers (useless, broke on first use... cast tin metal!) and some rings are included with the pad.
I used two pairs of long nose pliers to open/close the rings.

where did you get your hog nose pliers from? mine are from ace hardware and have worked fine for 8 sets of seats I've pulled apart to clean over the years (cloth seats).

though, hog ring pliers are only to be used to squish new hog rings, not pull apart old ones as they are used to mend barb wire fences originally. I've always used needle nose pliers to pull apart old hog rings. just grab one side and pull/twist normally rips them out super easy.

[Turbo_Bimmer]

Originally Posted by stackz

where did you get your hog nose pliers from? mine are from ace hardware and have worked fine for 8 sets of seats I've pulled apart to clean over the years (cloth seats).

though, hog ring pliers are only to be used to squish new hog rings, not pull apart old ones as they are used to mend barb wire fences originally. I've always used needle nose pliers to pull apart old hog rings. just grab one side and pull/twist normally rips them out super easy.

Mine came with the heating mat. It was a VERY cheap tool made of thin metal or so. It broke at the 3rd ring I installed! I've seen some 'more professional' pliers on EBay, for more money...

[jeepo23]

I might have found a source that can actually get us the BMW pads, spec wise.. the size of the mat might still be a bit different but wattage and resistance values are the same.

Basically the pad is 50x27cm, 3 wire, 30watts, 10k resistance for the temperature sensor (this is what that BMW sensor is at also). $30.

They can also create a 50watts pad, however that would be slightly more, $40 for two pads. These pads are also with alloy wire and not carbon fiber inserts.

My question, are the BMW pads 50watts, each for the backrest and bottom? Or is it 50watts total combined between the two pads?

Also, I am unsure of this alloy wire vs. carbon fiber stuff how well it will work.

[Turbo_Bimmer]

The pad I measured was 50W for the seat mat by itself.
If you choose a 30W mat, make sure to install it over the old mat, like I did, so it is a close as possible to the leather.

[jeepo23]

Originally Posted by Turbo_Bimmer

The pad I measured was 50W for the seat mat by itself.
If you choose a 30W mat, make sure to install it over the old mat, like I did, so it is a close as possible to the leather.

Thanks Turbo! I think I'll just go with perhaps the 30W matt. Any recommendations on would it be better to go with one that comes with 3 wires or 4 wires?

Due to my scenario not knowing whether or not my actual sensor even works I might have to use the one that comes with this new (Verified that apparently its also 10k) I'd say it would be much wiser to go with 3 wires, correct?