Member Since: 20 Oct 2012
Location: Wokingham
Posts: 107
Diagnosing heated seat faulty heated seat
Hi,
I'm looking for some advice on how to approach diagnosing a fault with the drivers heated seat.
a) Drivers seat base and back do not generate heat.
b) Heating control on dashboard appears to work, starting on 2 lights and dropping to 1 after some period of time
c) Passenger and rear heated seats are all working
d) Fuses in engine bay related to seat heating are ok.
My suspicion is that it's the element, but would have expect either the base or the back heating to fail separately, but not sure exactly how the system is configured. Having said that since we've just bought the car I guess it's possible both elements have failed independently.
I've an AutoEnginuity ODB2 scan tool, but currently only licensed for BMW, I'm planning on adding Land Rover support, but haven't yet. However if there is a simple approach, i.e. check connector X pin Y it should read Z Volts or something to at least confirm the fault is the element(s) so I don't spend time getting the parts ready to pull apart the seat...
Both elements are separate and both are on there own plug that is in the large connector under the seat, its held together with a bolt that when you undo it it draws the the two halves of the socket apart, just look for the one with a black plugs on them these are the heated seat elements connectors, you can check for continuity and if there is a supply to the plugs..
Flack
27th Oct 2012 11:01 pm
shortbloke
Member Since: 20 Oct 2012
Location: Wokingham
Posts: 107
Thanks Flack, will take a look tomorrow. I took a brief look earlier under the driver seat and it was a mass of wires and connectors. I'm not sure if these are all do do with the driver memory seats of if some part of the HK system is also under there.
Your description of the connector should make it easier to identify, thanks. Martin
Martin if you look in my gallery there is a picture of the seat's main connector, and yes under your seat is the amp but all the wiring for that is at the back of the amp ..
Flack
28th Oct 2012 12:45 pm
shortbloke
Member Since: 20 Oct 2012
Location: Wokingham
Posts: 107
Thanks Flack.
So I took a look this evening.
The first step was to remove the plastic fascia panel under the drivers seat. This is removed by simply pulling hard.
This exposed the connector you mentioned which is opened with a 7mm socket.
This connector block contains many connectors. I'm not exactly sure which connector in this block is for the seat element, but based on some other threads I believe it's the black connector on the right of the connection block with 4 pins.
Looking at this connector block and number the pins:
12
34
Between 2 and 3 it reads 8k Ohms
Between 1 and 4 open circuit.
I checked my passenger side connector and between 1 and 4 it read close to 0 Ohms, with 8k Ohms as the driver side for between 2 and 3.
Am I looking at the right connector?
Does anyone know if this points to one element or the other?
Picture below to hopefully explain further what I'm talking about
Driver side connector block
Close up of the right hand connector
28th Oct 2012 8:42 pm
shortbloke
Member Since: 20 Oct 2012
Location: Wokingham
Posts: 107
My workshop manual arrived today
Looking at the diagram it appears the seat elements are wired in series and the 8k ohm load I was seeing on both driver and passenger seats would have been the thermistor.
Click image to enlarge
As these are in series is there any connection someone that allows me to test each independently? The circuit diagram doesn't show any number connection points.
29th Oct 2012 1:14 pm
shortbloke
Member Since: 20 Oct 2012
Location: Wokingham
Posts: 107
Ah there is another connector!
I found in another users gallery a picture of the cables that come with the seat base element. It shows the large black one that I'd been testing above, but also a white connector that connects to the seat back element.
This is secured to the seat base in a fairly inaccessible place, I just had to feel where the cable went, found the connector and felt round till I figured out how to release it.
For reference from the middle row of seats I found the connector secured on the left hand side of the seat base.
Once removed I checked and found good continuity through the seat back element, so looks like it's just the seat base element to replace.
However I'm wondering if a new seat base pad might not be a bad idea either, as the current one lacks any sort of real support from the seat bolster.
30th Oct 2012 6:33 pm
parrafin23
Member Since: 04 Dec 2011
Location: Buskeud
Posts: 678
Member Since: 20 Oct 2012
Location: Wokingham
Posts: 107
Thanks parrafin, I think I found your thread in one of my many searches through the forums. I assume you've not had problems with your element repair (rather than replacement)?
I've got the quote for parts from TLO but maybe a repair rather than replacement is viable...
I need to get the seat pad off and have a look. I've had a quick go a undoing the torx seat pad bolts but stopped as I was worried my Halfords torx bit was damaging the head. I've ordered a 1/2" torx bit in the hope I'll have more leverage with a longer ratchet.
Then again it might be easier to remove the whole seat and get easier access to those bolts.56 D3 HSE / 05 Porsche Boxster S
31st Oct 2012 6:22 pm
parrafin23
Member Since: 04 Dec 2011
Location: Buskeud
Posts: 678
I asked my local indy about a new heat element. they told me that the replacement element did not give the same amount of heat as the one installed. so just drop it was hees advice.
Thats why I ripped open the seat and had a look.
When I found these 2 burnt wires i just put on a crimping hose and twisted the wires together. But not tight, due to the movement it needs when you put your rear end on it.. So I let i be a bit slack and shrinked it and it stil goin Hot? ye.. nice and warm. hmm.. its been a year soon.. a durable fix. Just a note.. if you go for the fix, just be prepared for a burning smell the first time you use the heat.. the foam gets a bitt melting hot.. so turn it on, wait for the smel, turn it off and let it cool.. do this again untill the smell no longer exists.
So got an issue?
Get a tissue or post here..
P.
2nd Nov 2012 7:13 pm
shortbloke
Member Since: 20 Oct 2012
Location: Wokingham
Posts: 107
Finally got round to tackling this job at the weekend.
Firstly getting the seat base bolts out was a pain. I had long and short torx bits but still found it awkward to get a clean straight contact on the bolts. One of the two rear ones I messed up a couple of weeks back when I first tried to remove the base. The second rear bold head rounded out when I tried to undo it. So in the end I unmounted the whole seat frame from the chassis and cleanly removed the front two bolts. I tried again on the rear bolts but their heads were rounded out. So I set about drilling them out. It took ages using drills bits of different size. The head is soft enough to round out, but you go a few mm deeper and the metal appears much harder. Anyway I finally managed to remove one of them. I was starting on the next when I had a brainwave, I wonder if a set of molegrips could get a good grip and get the leverage needed to remove it.
Quick rummage around the toolbox and back to the car with grips in hand, 30 seconds later the bolt was out. So top tip, before anyone think about drilling these bolts out, try some molegrips.
So with seat base removed I returned indoors to start removing the leather, this was straight forward from following information on the site: http://disco3.co.uk/forum/topic37748-15.html
I'd ordered a new seat base pad and element from TLO, in the hope the new base might have more side support (it doesn't). So removes the hogrings securing the leather cover to the base and decided to strip the element off my old seat to see where it was broken.
It was on the right hand edge of the pad, the element had been stuck down with one of the wires going over the edge of the side pad bolster, I suspect the pressure and movement of that area made it a weak point. So carefully stuck down the new element to the new pad re-attached the leather seat cover. Then installed it back in the car with the 2 good seat bolts and the 1 reinserted with molegrips.
I've just ordered a couple of replacement bolts from TLO to replace the drilled and damaged one, to be fair I should only need one, but I figure I might at well restore it properly.
Good news, everything back in place and most importantly working
I just need to work on being less hamfisted 56 D3 HSE / 05 Porsche Boxster S
24th Dec 2012 12:01 pm
Undertaker
Member Since: 10 Nov 2013
Location: Cumbria
Posts: 7
I have exactly the same problem, what an excellent post. Where can I buy a new base and element?
24th Nov 2014 10:05 am
shortbloke
Member Since: 20 Oct 2012
Location: Wokingham
Posts: 107
If you PM "The Large One" aka TLO he can sort you out with all the parts you want/need. Martin56 D3 HSE / 05 Porsche Boxster S
24th Nov 2014 10:14 am
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
Yeovil Land Rover is still there but TLO now makes Chilli Sauce for a living. Although the sauce can also keep your bum quite warm with localised hot spots.
Land Rover - Turning Drivers into Mechanics Since 1948
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