DIY: Heated Seat Repair - with pics - BMW M5 Forum and M6 Forums

Go Back   BMW M5 Forum and M6 Forums > BMW M5, M5 Touring, M6 and Z8 Forums > E39 M5 and E52 Z8 Discussion

E39 M5 and E52 Z8 Discussion 1998-2003 Advertiser's Forum

Like Tree1Likes

Reply
 
LinkBack Thread Tools Rate Thread Display Modes
Old 30th October 2011, 14:22   #1
peritus
Member
 
peritus's Avatar
 
Join Date: Sep 2011
Location: Toronto

Garage: Porsche 911 Black on Black

Sales Feedback: (0)

Thanks: 6
Thanked 0 Times in 0 Posts
Heated Seat Repair - with pics

I'll start out by saying the title at this point is misleading, since I have not completed the repair. I'm waist deep, and I've been taking pics. Hopefully the process of me figuring this out will help others with the heated seat issue and things you can do to diagnose different components.

So, I bought a new (to me) BMW E39 M5 last Tuesday - MY2000 with about 70k miles. It's awesome. It's cold in Canada though, and heated seats are a luxury that I cannot go without. On my first official drive, I pressed the heated seat button and the lights on the button shut off.

I pressed the sunshade and it didn't work. The passenger side didn't work either. So, I tracked down a 25amp fuse (slot 32) and it was blown.

I determined it was the driver seat heater because when I replaced the fuse, the passenger seat heater and sunshade were functional. When I'd turn on the driver seat heater and the fuse would go.

I searched the forum and learned that the heating element pad in the seat can go with age and use, and can cause a short to a ground and a blown fuse.

I tried jiggling the wires under the seat but that did not work. So, out comes the driver's seat.

Required tools:
-torx set, including extension
-screw drivers
-pliers
Attached Thumbnails
Heated Seat Repair - with pics-dscf3200.jpg  

Heated Seat Repair - with pics-dscf3207.jpg  

__________________
James

Audi Allroad twin turbo (GIAC Tune 360 hp)
Porsche 911 C4 (DD)
BMW M5 E39

Last edited by peritus; 30th October 2011 at 15:20. Reason: typo
peritus is offline   Reply With Quote
Old 30th October 2011, 14:32   #2
peritus
Member
 
peritus's Avatar
 
Join Date: Sep 2011
Location: Toronto

Garage: Porsche 911 Black on Black

Sales Feedback: (0)

Thanks: 6
Thanked 0 Times in 0 Posts
Having no experience with upholstery, I basically went at it, unscrewing and dismantling everything that was in my way. I have a screwdriver set with the torx fitting. Without that tool, I would have really struggled with getting access to some of the fasteners. You really have to search around for the fasteners too, because they can be hidden, such as on the driver side moulding.

Then, you just have to pull the leather off the little hooks on the frame by depressing the foam to give you some slack... one by one. It's been pretty easy so far!
Attached Thumbnails
Heated Seat Repair - with pics-dscf3208.jpg  

Heated Seat Repair - with pics-dscf3209.jpg  

Heated Seat Repair - with pics-dscf3210.jpg  

peritus is offline   Reply With Quote
Old 30th October 2011, 14:36   #3
peritus
Member
 
peritus's Avatar
 
Join Date: Sep 2011
Location: Toronto

Garage: Porsche 911 Black on Black

Sales Feedback: (0)

Thanks: 6
Thanked 0 Times in 0 Posts
Ok, so I encountered the "whoops I should have done this first" problem... The thigh support was not retracted, so I couldn't get access to the leather... so, back in the car the seat goes... I actually had to connect the whole harness and controls one the side for the seat to be operational. I extended the thigh support and put it back on my work fridge.
Attached Thumbnails
Heated Seat Repair - with pics-dscf3212.jpg  

peritus is offline   Reply With Quote
Old 30th October 2011, 14:45   #4
peritus
Member
 
peritus's Avatar
 
Join Date: Sep 2011
Location: Toronto

Garage: Porsche 911 Black on Black

Sales Feedback: (0)

Thanks: 6
Thanked 0 Times in 0 Posts
So, the only thing that is scaring me now are the hogtie clips. The are little metal rings that have been bent to suture the leather to anchor points on the chassis of the seat. They are really easy to take out.. easy like breaking a window... not that easy to put back together.. anyway, I'm in this deep, I'm not about to let those little rings deter me.

At this point, I'm thinking the repair will be as easy as going down to the BMW dealership close to my house and getting a new pad, popping it in and reassemble...

But, despite what other threads on the subject have said, the heating pad is not separate! It's actually sewn into the leather!! So, off to the stealership. New leather with heating pad sewn into it... $1,510.00. No thanks. It was like pulling teeth to get them to tell me about the pad I know they sell. It basically fits under the OEM non working pad and has a harness.

The downside could be that it takes longer to heat the seat because it has to old one to heat through.. but whatever, it'll work at least. I can wait another 3 mins to have warm buns.

So, I ordered a heating pad insert for $175 and bought new hogtie clips for $0.54 each. Problem is, it's not in stock.. It's on back order and may have to be ordered from back home in Germany. Such is life, I can wait.

Last edited by peritus; 30th October 2011 at 15:24.
peritus is offline   Reply With Quote
Old 30th October 2011, 14:54   #5
sproule905
Member, Sport: On DSC: On (>100 posts)
 
Join Date: Oct 2011
Location: Toronto
Age: 34

Garage: 01 M5 - CarbonSchwarz Metallic on caramel

Sales Feedback: (1)

Thanks: 9
Thanked 2 Times in 2 Posts
hey man.

I see you are in TO. I am just up north in Holland Landing and recently purchased an 01 M5. Mines never been winter driven, but the heated seats turn on and heat up so fast my *** gets burned. On my morning drive I have to have the setting on the lowest.

I hope to not go through what you are going through, but best of luck!

Seems like you might have this figured out! and you are right, heated seats are a requirement up here!
sproule905 is offline   Reply With Quote
Old 30th October 2011, 15:01   #6
peritus
Member
 
peritus's Avatar
 
Join Date: Sep 2011
Location: Toronto

Garage: Porsche 911 Black on Black

Sales Feedback: (0)

Thanks: 6
Thanked 0 Times in 0 Posts
So at this point, all I can do is wait a few weeks. I go home and look at the mayhem I caused with my seat.. hoping that I'll be able to even remember to put it back together.

Then, I look at my previously assumed faulty heating pad. Everything I read said that the heating element is shorting out on something, but if it's contained within the pad, how is that possible? I suppose they could have gotten hot enough to melt some wire coating and short out against themselves, but I'm beginning to question that there is any issue with my heating pad.

I put the seat back in the car with the leather un-attached. Then, my buddy who was helping me inquired about the actual switch on the center control unit... um... well I hadn't really thought of that..

I decided to be a junior scientist and but some basic testing to work. My plan is to switch the dirver and passenger switch, but I quickly find out that it's one unit and cannot be done. I tried to take it apart, but it's locked and all I can see is a circuit board inside.

With everything plugged back in properly, I put the seat heater on but did not sit in the seat, thinking that without my weight there, it would not short out as it has during my last 20 tests with 20 blow fuses. It stayed on! It stayed on and got hot for 25 minutes! Maybe it was a lose wire in the centrol control unit or the harness behind it. I don't care.. it works!

Maybe it's not the pad after all! I get in the car and drive. Toasty warm buns, I call my dad and brag about my DIY repair. I get off the phone and snap.. the fuse goes.

So, I think now that it is the control unit. The switches have a lifespan and when they get hot enough they'll burn out and blow a fuse.

So here I am now. Not 100% sure it's the heating pad or the control unit. I don't have an ohms meter small enough to test the pad, and I have no idea how to test the control unit. Anyone in Toronto that wants to swap control units for 15 minutes would solve my problem, but I don't know anyone local with an E39 M5. (speak up LOL)
Attached Thumbnails
Heated Seat Repair - with pics-dscf3213.jpg  

Heated Seat Repair - with pics-dscf3214.jpg  

peritus is offline   Reply With Quote
Old 30th October 2011, 15:06   #7
peritus
Member
 
peritus's Avatar
 
Join Date: Sep 2011
Location: Toronto

Garage: Porsche 911 Black on Black

Sales Feedback: (0)

Thanks: 6
Thanked 0 Times in 0 Posts
I will update when I get to the next step... if anyone knows where I can get a used control unit, please hollar. If someone would be knd enought to lend me theirs, I'd super appreciate it.

I hope this has helped someone with the same problem!
Attached Thumbnails
Heated Seat Repair - with pics-dscf3215.jpg  

peritus is offline   Reply With Quote
Old 30th October 2011, 15:30   #8
peritus
Member
 
peritus's Avatar
 
Join Date: Sep 2011
Location: Toronto

Garage: Porsche 911 Black on Black

Sales Feedback: (0)

Thanks: 6
Thanked 0 Times in 0 Posts
I'm in Vaughan... can I borrow your control unit for a few minutes to rule out that mine is effed? It's very easy to take out -it's only 2 screws.

Thanks

Quote:
Originally Posted by sproule905 View Post
hey man.

I see you are in TO. I am just up north in Holland Landing and recently purchased an 01 M5. Mines never been winter driven, but the heated seats turn on and heat up so fast my *** gets burned. On my morning drive I have to have the setting on the lowest.

I hope to not go through what you are going through, but best of luck!

Seems like you might have this figured out! and you are right, heated seats are a requirement up here!
peritus is offline   Reply With Quote
Old 31st October 2011, 03:12   #9
OC e39r
m5board.comoholic (>1000 posts)
 
OC e39r's Avatar
 
Join Date: May 2008
Location: California

Garage: M5 Alpine White

Sales Feedback: (6)

Thanks: 96
Thanked 116 Times in 97 Posts
Quote:
Originally Posted by peritus View Post
I will update when I get to the next step... if anyone knows where I can get a used control unit, please hollar. If someone would be knd enought to lend me theirs, I'd super appreciate it.

I hope this has helped someone with the same problem!
Those ppl can help you, no affiliation but a friend has good few experiences with them..

Euro-Depot BMW Dismantler & Discount BMW Parts
__________________
Running strong

Hüper Optik 40%
E60 545 shifter
E53 X5 front control arm bushings
E9x radio knobs
E46 m3 alcantara steering wheel
Eibach rear sway bar
Koni yellows
CNS 10.5 clutch disc with a lightened dual mass flywheel
Carbotech 1521 pads
StopTech SS brakes lines
Centric high carbon rotors
Intravee II,Alpine KCA420i
Cupholders delete
Pre facelift headlights with BMW historic amber signal
OC e39r is offline   Reply With Quote
The Following User Says Thank You to OC e39r For This Useful Post:
peritus (7th November 2011)
Old 31st October 2011, 03:57   #10
JDMM5
Member, P500 Sport, DSC On (>700)
 
Join Date: Mar 2011
Location: Athens, Ga
Age: 41

Garage: 2002 M5 LeMans Blue

Sales Feedback: (0)

Thanks: 117
Thanked 96 Times in 79 Posts
Not saying that a circuit within the control unit isn't bad and causing your problem, but when switches themselves go bad they usually DON'T blow fuses- they just burn their contacts and/or stop working. A low resistance path to ground is blowing your fuse.

You really ought to investigate every visible wire you can get at very closely. The contact area can be extremely small but will usually show a small char/burn area where it is contacting ground. You will need to remove them from the bundle to do this. It could be that two adjacent wires are shorting with each other leading to the heat elements rather than the elements themselves shorting out. Not to say it isn't the elements but you'll want to be sure it isn't before you give up and go to plan B which is less than perfect, IMO.

If it were me I'd get the seat heating elements in a position where it will work without blowing the fuse like you did earlier and then carefully move the wiring around a section at a time and apply seat pressure or whatever until the fuse blows again. That should give you a general area to look at. Since you'll only be troubleshooting the driver's seat, you can get away with a lower rating fuse (maybe half) during the troubleshooting process only. You can do that because the passenger seat will not be used during this time. Doing that will lower the current carrying stress on the rest of the otherwise unaffected wiring until you figure out the problem. Just my opinion.

I have other and more practical ways to find shorted wiring but requires investment in some moderately expensive equipment, other than just a digital multimeter.

Last edited by JDMM5; 31st October 2011 at 04:13.
JDMM5 is offline   Reply With Quote
The Following 2 Users Say Thank You to JDMM5 For This Useful Post:
peritus (7th November 2011), Sailor24 (31st October 2011)
Reply

Bookmarks



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Heated seat buttons cracked kamm121 E39 M5 and E52 Z8 Discussion 8 30th October 2011 05:46
Heated Seat Distribution bloomjbmw E60 M5 and E61 M5 Touring Discussion 5 22nd October 2009 07:13
Heated seat problems vev78 E39 M5 and E52 Z8 Discussion 2 22nd April 2007 01:38
Heated Seat GoneAgain E34 M5 Discussion 5 23rd October 2006 18:55
Heated-seat problems? DrJimM5 E39 M5 and E52 Z8 Discussion 5 4th December 2000 06:47

Loading...

All times are GMT +2. The time now is 07:45.



Everything Copyright 2000-2008. Do not use ANYTHING from this site without written permission. All images, graphics, sound files, video files and text appearing on this web site are the exclusive property of m5board.com and are protected under international copyright laws. All images, graphics, sound files, video files and text on this site are for on-screen and on-site viewing and listening only. No part of this web site may be reproduced, copied, saved, stored, manipulated, or used in any form for personal or commercial purposes without the prior written permission of m5board.com. Use of any image or graphic as the basis for another photographic concept or illustration is a violation of the copyright. Any copyright infringement will be prosecuted to the full extent of federal and international copyright laws. M5board.com is an enthusiast board and we don't condone any dangerous activity. Our airfield events are completely safe based on years of experience, we conduct them during clear visibility with mature participants that have several years of experience with high-performance automobiles, large unobstructed run-off zones on sealed off private former military airbases and we clearly mark the braking zones. If inexperienced with high speed driving we do not recommend organizing your own event but attending a high-performance driving school. The use of the term "BMW" on this site is for reference only, and does not imply any connection between m5board.com and BMW AG or BMW North America.