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RRC Electric Memory Seat

14K views 20 replies 5 participants last post by  Simplysimon 
#1 ·
Hello, new member so go easy on me... I have a 1992 Vogue SE and (perhaps unsurprisingly) the driver's memory seat does not move. From reading the various posts in the forum, I'm pretty sure it's the ECU that's shot (mirrors also don't operate).

The seat is in the perfect position for me so it's not bothered me in the past, but it's just failed the MOT because of the inoperable seat. One option would be to get the ECU rebuilt, but are there any (cheaper) alternatives to get it through the MOT? I'm not bothered about the memory function, so is there a way of directly wiring the switch to the motor just to get it moving back and forth (I only need fore and aft adjustment for the MOT)? Alternatively, would it be relatively straightforward to fit a manual adjustment seat if I could get hold of one, and does anyone know if a series 1 Discovery seat would fit?

Thanks in advance for any help.

Matt
 
#2 ·
Yes, it is possible to wire the switch directly to the motors. I did it on a friends 95 soft dash LSE for exactly the same reason you need it to work, to get it through the MoT. I also on wired the forward reverse switch but with a bit more effort (and wire) it would be possible to wire all motors if you really wanted to. I'll dig out the diagram I drew for myself. Where in the world are you? UK I assume with reference to MoT (and failing on a seat that doesn't move) so if nearby I'd be happy to do it for you.
 
#4 ·
Thanks for the responses, that's great. I must admit I've not looked at the ECU yet so it might be salvageable... although the seats have never worked in my ownership (6 years)!

Richard G - if you could dig out the wiring diagram that'd be great. I'm based near Derby if that's near to you? If not I'll probably take a look over the weekend...

Thanks again, great forum!
Matt
 
#5 ·
If the seats haven't worked in 6 years and the mirrors don't work either, then the ECU is probably way past repair. I've repaired 3 now and the first two were simple, just replace the battery and a couple of tracks under the battery. The last one needed the two ICs next to the battery removing, the pcb tracks under them had to be pieced out and the ICs replaced. All worked after this but on all of them although the seats didn't work the mirrors still did. In fact, if you tried to move the seats they didn't move but the mirrors did. I've got spare batteries and ICs so can have a look at it if you want but I wouldn't hold out much hope in all honesty.

Anyway, you can get the seat to move without the ECU. This mod involves wiring the motors directly from the switches. When I first did it I was concerned that the switches may burn out switching the amount of current that the motors draw but they have survived for over a year now. I suppose it isn't something you use often though but if the car was going to be used by different people so the seat was constantly being adjusted I'd fit relays to switch the motors. With a bit more wiring it would be possible to get all the motors working but most wouldn't find it necessary.

To connect to C328 you'll need some round female connectors. I used butt joints insulated with heat shrink, for C324 you need small spade terminals. Where you have to snip the two wires make sure you insulate the ends.

Text Diagram Line Circuit component Parallel


Text Crossword Font Toy Puzzle


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If the seat goes forward when you tell it to go back and back when you tell it to go forward, swap the two wires on pins 1 and 9 on C328 over.
 
#6 ·
In case you have difficulty working out which of the two wires need to be snipped, coming off C234 are three separate cables that go to the seat switch. There's a 3 way with grey, grey/purple and grey/green which goes to C237 which can be ignored. There's one with 6 wires, green, yellow, red, orange, purple and black which goes to C236 which you also don't touch and finally, one with 5 wires, purple, orange, red, yellow and black/yellow that goes to C235. It is this last one where you snip the red and yellow wires.
 
#7 ·
Thanks so much for that - amazing detail. The explanation and diagrams are really clear even to a novice like me so I'll take a look tomorrow. Might have a few more questions once I'm faced with a mass of wires though! First job will be to move the seat to actually get at the thing...
 
#10 ·
To get the seat out you'll need to move it back to get at the front bolts on the runners. If you grope under the seat and find C238, the blue connector that goes to the motors (easier from the rear footwell), you can unplug that, connect two wires to pins 1 and 9 and put power on them to move the seat back and forth. Connect power one way round to go forward and the other way round to go back. It's easier if you have a spare battery and can just connect your two wires to that.

The 12V power can be picked up from any 12V supply, but if you want to keep things anything like sensible, pick up the power from F4 in the drivers underseat fusebox (if it exists on a 92, my diagram is for a 95) which is the seat supply and goes to pin 9 on C302. It should be a white/grey wire and C302 is the big white 24 way plug that goes to the seat ECU. Ground can be picked up anywhere, just attach it to any metal bit under the seat if you can't see an actual ground point. I think I just put a ring terminal on the end of the wire and put it under the screw head of a screw that was holding something in place.
 
#11 ·
I had a good poke around under the seat to get my bearings before cutting any wires. When I looked at the c328 connector, it looked like the attached photo, with all 4 wires from the top terminals being green, and the 4 wires from the bottom terminals being yellow. Using the numbering from your drawing, it is 'hole' 9 rather than 'hole' 5 that has no terminal. So it's a bit different to your drawing.

Do you have any ideas which two terminals would connect to the forward/backward motor? If not, would the easiest way be just to put a 12V car battery supply across the various combinations of yellow/green wires until I find the right one?! I assume that it should make no difference whether the car ignition is 'on' if I am just powering the motors directly?

Again, sorry for all the (basic) questions, it's really, really helpful and does make sense!

Thanks
Matt
 

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#12 ·
The diagram I posted would appear to show the other connector, the female side rather than the male pins so you have to imagine that the diagram is showing you the back of the connector rather than the connector side you are looking at. The two you need are the two end pins at the right hand side of the picture. This id down to a slight difference in the diagram for a Classic than for a P38 or later model. The Classic diagram shows that connection as C328, whereas the diagram for a later car would show it as C328 and whatever the other plug that it connects to would be designated as so there would be two numbers for each connection point. Yes, you can just put 12V across the various green/yellow pairs, there's 4 motors, forward/back, seat front up/down, seat rear up/down and seat backrest recline/upright. If using a separate battery to operate the motors it doesn't matter if the ignition is on or off, in fact it doesn't matter if the car even has a battery connected at all.

@mud4fun, I've got a complete factory manual for 87-92 and the 93 was identical to a 92 as it was the last year before the softdash which came out in 94 (although was considered a 95 model). PM me an email address and I'll send you a link to it.
 
#14 ·
Hello again, apologies for the lack of update. I think I've got everything together now, and planning on tackling it in the next couple of days. I'm planning on piggy-backing the 12v supply from one of the underseat fuses, as you suggested. Do you know which one of the three in the picture below is for the driver's seat, and what size fuse I should use in the 'bypass' circuit? Thanks, Matt
 

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#15 ·
So, it appears that I didn't have the right fuses in my last post! I understand from reading around that the electric seat fuses are the 30A ones in the black box pictured below. I know I should have checked this right at the start, but there appear to be two missing! Does anyone know which two are missing, and which one is for the driver's seat? I think they are called F1-F5, but don't know whether F1 is on the left or right, and couldn't see it written on the box. The picture is taken from the back, looking forwards. Any help or clues much appreciated! Thanks again. Matt
 
#16 ·
The fuse boxes, locations and designations seemed to change about every 6 months so which fuse you use is pretty much irrelevant as long as it can supply the amount of power you need. However, F3 is one of the 30A fuses that feed the seats and that has a white/yellow wire coming off it that would go to the seat ECU. So the one shown on the right on your picture would seem to be the right one.
 
#17 ·
Dragging this thread back up but I've had a PM from a new member (gregkrusz) asking about the diagram for this mod. Unfortunately, he has set his preferences to not receive Private Messages so I can't rely to him. So, in the hope that he sees this and that it may help others with teh same problem, here's a diagram:

Text Diagram Line Circuit component Parallel


This only allows the seat to be moved back and forward but with a bit more snipping and re-wiring it would be possible to get all motors wired to the switch. No worries about burning the switch out as cars with the non-memory seats don't have the ECU so the switches are connected to the motors directly.
 
#18 ·
Dragging this thread back up but I've had a PM from a new member (gregkrusz) asking about the diagram for this mod. Unfortunately, he has set his preferences to not receive Private Messages so I can't rely to him. So, in the hope that he sees this and that it may help others with teh same problem, here's a diagram:

View attachment 273864

This only allows the seat to be moved back and forward but with a bit more snipping and re-wiring it would be possible to get all motors wired to the switch. No worries about burning the switch out as cars with the non-memory seats don't have the ECU so the switches are connected to the motors directly.
 
#19 ·
Hi Richard,
I’ve just joined the forum/group!
I tried sending you a message directly but this wasn’t allowed for some reason so hopefully you’ll see this in this discussion, albeit a couple of years old!
I have an NZ new 1994 soft dash classic.
Until a short while ago my driver’s seat was working but now controls the mirrors only.
I’ve read up online about the ECU issues but was far more interested in your conversation with someone about rewiring.
I’ve copied and pasted most of that conversation and I wondered if you had worked out how to also rewire the other motors so that save the blessed 2 X memory function, the seat could operate as intended.
Would you have wiring instructions for those?
I have absolutely no skill in any of the above but assume a good auto electrician would be able to do the job? Or maybe someone that fixes old radios?
Many thanks in anticipation
Regards
Simon
 
#20 ·
If your seat has only recently stopped working, then it is likely that all that is needed is the battery being replaced in the ECU. There may be the odd corroded track underneath it but that will be about all so any reasonably competent electronics engineer should be able to do it. Someone who fixes radios, as long as they are used to working on printed circuit boards anyway. You've nothing to lose, if it works, great, if it doesn't you haven't lost anything. I'll admit I never bothered to go beyond the diagram you have found in this thread but it isn't that difficult to work out once you get your head around how it works.

The reason you couldn't send a message directly was your registration was still waiting to be authorised by an Admin or Moderator. So not only have I authorised you, I've replied as well, what more could you ask for?
 
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