Unfortunately, having had four bouts of back surgery over the years I find that there is not enough lumbar support in the design of the seats. I have tried my old remedy of a back support but as it has the opportunity to slide down between the squab and back rest, it does. Therefore I am exploring changing the seats out for XJ 40 seats which have lumbar and waist support and am trying to inderstand the wiring diagram. I think i have it but if anyone has done this change and has some knowledge of the wiring diagram I would appreciate the chance to discuss it further. Fingers crossed as i will only have one chance to get it wrong. DC can be very unforgiving.XJ40 seat wiring
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Just searched the forum but cannot find any answers so i could do with the benifit of someones experiance. Having recently finished my rebuild of a 1968 240 I have completed the first 500 miles of running in, without hicup thankfully, head retorqued, another 1500 to go
Unfortunately, having had four bouts of back surgery over the years I find that there is not enough lumbar support in the design of the seats. I have tried my old remedy of a back support but as it has the opportunity to slide down between the squab and back rest, it does. Therefore I am exploring changing the seats out for XJ 40 seats which have lumbar and waist support and am trying to inderstand the wiring diagram. I think i have it but if anyone has done this change and has some knowledge of the wiring diagram I would appreciate the chance to discuss it further. Fingers crossed as i will only have one chance to get it wrong. DC can be very unforgiving.
Unfortunately, having had four bouts of back surgery over the years I find that there is not enough lumbar support in the design of the seats. I have tried my old remedy of a back support but as it has the opportunity to slide down between the squab and back rest, it does. Therefore I am exploring changing the seats out for XJ 40 seats which have lumbar and waist support and am trying to inderstand the wiring diagram. I think i have it but if anyone has done this change and has some knowledge of the wiring diagram I would appreciate the chance to discuss it further. Fingers crossed as i will only have one chance to get it wrong. DC can be very unforgiving.
Re: XJ40 seat wiring
hello Doherto,
are the seat controls exterior to the seat?
I was thinking that generally the controls are seat mounted so all the wiring will be there and a suupply is all that is necessary? Do you have a diagram that you can post here?
Alec
are the seat controls exterior to the seat?
I was thinking that generally the controls are seat mounted so all the wiring will be there and a suupply is all that is necessary? Do you have a diagram that you can post here?
Alec
Mk 2 3.8 (long term restoration), MK1 Triumph 2.5 P.I. , 564 Hymer Motorhome
Re: XJ40 seat wiring
Alec thank you for you reply. I have attached a link to the diagrams I am looking at. I have a contact who has seats from this model to sell but unfortunately I do not know if they are memory or not. I will find out on Tuesday. I assume if not, all the wiring will be in the base if they are then I would hope to remove or not use the memory facility. If you look at the non memory diagram, about page 174. 14.3, I believe, from the top down, WN is an ignition earth, NO NG NLG and NS are all 12 volt positive and WP is an ignition 12volt positive. My first question is what to do with the two signal wires K and O I assume I can just then earth the five switched earths below them. If they are memory there seams to be two diagrams ROW and NAS. 14.1 and 14.2 and I have no idea what that means. Something simple I assume. Anyway as the non memory seams to leave the five connections to the memory switches open circuit then hopefully I could just disconnect the module. So if I am right with the power connections and my theory of removing the memory facility is correct it’s just the question of the two ‘serial connections’ Hopefully this all makes sense
Re: XJ40 seat wiring
I have fitted what I understand are *** XJ40 seats, with picnic trays.(*** I purchased the seats loose with the car). My understanding is that the ones I have are from the top spec XJ40 with heated seats and head rests with integral interior lights. The head rest lights need a supply from the side lights, but the head rests are fixed and non adjustable in the XJ40 models.
I eliminated the heated seat wiring, but retained the electric tilt. The tilt is controlled by reversing the polarity from positive to negative and an electric window switch is ideal. I obtained my switches from Holden Electrics, part no. 020.205 they fit into end surround fixtures part 020.221 and use connector kit 020.222. You need these parts with each switch. These switches reverse the polarity automatically to tilt the seat upright or back down.
From memory the seats are wired with an earth, live, and up and down wires. A heavy connector supports the wires for the heated seat (which I cut out) and another feeds the head rest light. They are easy to check out with a test lamp. Once you find the live all you need do is to connect across the test lamp to find the earth wire. Then connect one of the remaining two wires to the live to establish which way it tilts the seat. The remaining wire tilts the seat the opposite way.
I fused the live feeds and lights, the latter taken off the light circuit, I also coupled each seat wiring through seven pin trailer plugs so that I could unplug the wiring if I needed the seats out.
A few pointers.
The seat sliders require changing and it is best to obtain very low height sliders to increase the access aperture. I picked up directly on the original S Type seat mounts and then adjusted upwards with packers.
You need to give some thought to the position of the switches. The wiring at the switch rear is apt to foul, as the seat is slid back and forth, if the switch is on the centre tunnel side
Make sure the switches do not clash with the safety belt anchor or belt line.
Make sure the seat is mounted at the same angle as the original It can easily be mounted a little further rearwards, which lowers the seat for easier access.
Beware of the height of any rear cross bar under the seats. If such a bar is too high it is likely to shear the toes of a rear passenger, any accident, who will have the bar above their feet. It is safer and better to position any cross bar at floor level whereupon the rear passenger will have the bar under their feet.
These seats are thicker than the originals and therefore some rear leg room is lost.
Mount the seats as near the centre tunnel as possible to provide better access to the hand brake lever.
It is not necessary to mount the switches on the same side of the seats.
The job is easy to complete if you look at the finer detail on some ones car and I would certainly recommend that you do so.
I can thoroughly recommend changing the seats; they are much more comfortable and supportive than the originals. I would not be without them.
If you cannot obtain my type of switch from Holden I believe you will find any electric window switch may suffice, but ensure you have some sort of mounting and connector block to suit the switch.
If you want to see the car contact me through the club, I am based in East Anglia but normally travel fairly frequently to Matlock / Bakewell area.
Norman
I eliminated the heated seat wiring, but retained the electric tilt. The tilt is controlled by reversing the polarity from positive to negative and an electric window switch is ideal. I obtained my switches from Holden Electrics, part no. 020.205 they fit into end surround fixtures part 020.221 and use connector kit 020.222. You need these parts with each switch. These switches reverse the polarity automatically to tilt the seat upright or back down.
From memory the seats are wired with an earth, live, and up and down wires. A heavy connector supports the wires for the heated seat (which I cut out) and another feeds the head rest light. They are easy to check out with a test lamp. Once you find the live all you need do is to connect across the test lamp to find the earth wire. Then connect one of the remaining two wires to the live to establish which way it tilts the seat. The remaining wire tilts the seat the opposite way.
I fused the live feeds and lights, the latter taken off the light circuit, I also coupled each seat wiring through seven pin trailer plugs so that I could unplug the wiring if I needed the seats out.
A few pointers.
The seat sliders require changing and it is best to obtain very low height sliders to increase the access aperture. I picked up directly on the original S Type seat mounts and then adjusted upwards with packers.
You need to give some thought to the position of the switches. The wiring at the switch rear is apt to foul, as the seat is slid back and forth, if the switch is on the centre tunnel side
Make sure the switches do not clash with the safety belt anchor or belt line.
Make sure the seat is mounted at the same angle as the original It can easily be mounted a little further rearwards, which lowers the seat for easier access.
Beware of the height of any rear cross bar under the seats. If such a bar is too high it is likely to shear the toes of a rear passenger, any accident, who will have the bar above their feet. It is safer and better to position any cross bar at floor level whereupon the rear passenger will have the bar under their feet.
These seats are thicker than the originals and therefore some rear leg room is lost.
Mount the seats as near the centre tunnel as possible to provide better access to the hand brake lever.
It is not necessary to mount the switches on the same side of the seats.
The job is easy to complete if you look at the finer detail on some ones car and I would certainly recommend that you do so.
I can thoroughly recommend changing the seats; they are much more comfortable and supportive than the originals. I would not be without them.
If you cannot obtain my type of switch from Holden I believe you will find any electric window switch may suffice, but ensure you have some sort of mounting and connector block to suit the switch.
If you want to see the car contact me through the club, I am based in East Anglia but normally travel fairly frequently to Matlock / Bakewell area.
Norman
Re: XJ40 seat wiring
Norman thank you for your very useful reply. I have read it but will now reread a few times to digest fully. I am sure it will be clearer when I get the seats on Tuesday but your comment that your seats provide you with greater support is encouraging. Thank you for your offer to view your car but hopefully I will have it sorted by this time next week as I did have the opportunity to view one yesterday too.
Re: XJ40 seat wiring
Ok. Got the seats this afternoon and after a quick check of the wiring colours it looks like they are memory ROW. ROW. Rest of the world and NAS North American System apparently. Hopefully I will get a chance to investigate the wiring further tomorrow, if HTSBO has nothing in the diary for me 
will report back when I have some information
will report back when I have some informationRe: XJ40 seat wiring
OK we are all sorted as there was nothing in the diary. I have just wired them up on the bench so have not utilised ignition power and earth at this stage, and connected them directly for now. For reference for anyone else doing this the wiring is just basically power and earth and all other connections can be left disconnected and the motors all work without any external door switches. As per my earlier post, Brown Orange PL2-7, Brown Green PL2-4 , Brown Light Green PL2-6, Brown Slate PL2-12 and White Purple PL1-11( this is the ignition power supply) are all connected to 12 volt Positive. White Purple PL1-11, White Brown PL1-3 ( this is the ignition switch earth) and the three Blacks PL2-3, PL2-5 and PL2-9 are all connected to negative Earth. All the other connections in PL1 and PL2 some of which I thought I would need to be connected to Earth can be left disconnected. Turned out a lot easier than I thought it would be but thank you for your responses. Just the mechanics of bolting them down to figure out but that cannot be rocket science. Oh! and finding matching leather and getting them covered.
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