2003 s-type USA model.
On my drivers side seat the adjustment for moving the the seat up and down does not work. The front thigh, front to back and back tilt do work. When pressing down or up I can hear the motor engage. If I hold it the switch in either the up or down position the thermal overload cuts in on the motor because I hear nothing. When watching the motor I can see it move/shift but I can not see the shaft engage to move anything. But I also saw what looks like the shaft move as if it was a U-joint.

So the switch on the side seems to work and the motor is getting power but there is no movement. Before I start taking the seat out are there any thought what I should be looking for?

 

The worm gear may have travelled to far and disengaged its threads, resulting in the lack of motion. You may have to remove the seat in order to get a proper "look-see" at the issue...

 

Can't help with your specifics, but one gotcha to keep in mind when removing a seat. The seat contains a side airbag. IIRC, you're supposed to disconnect the battery first and then wait one minute before removing the seat connectors.

i don't care to discuss how I know this, but position the seat first so you can access the bolts to the floor. Put the recline forward, too. Adjust the steering wheel up and forward, too.

Before disconnecting the battery, make sure your key works on the trunk lid. I like to unlatch one of the rear seat backs, too. In a pinch, if the key failed, I could always crawl in to pull the emergency release

 

Mine's doing the same thing but on the passengers side front thigh back and forth adjustment..
Good advice from Karl's above post, that's for sure!

 

Thank you for the advise on positioning the seat before removing power.

I have watched the motor on the left side of the seat jump when trying to raise or lower the seat. The motor near the transmission tunnel I have not been able to see it move anything. I am guessing it moved the seat front and back. It has what looks like a shaft connect to the far side but I have not see it move.

The way the up down motor jumps it makes me think something within the mechanism is damaged or broken. I want to understand what I am looking at as best I can so I know what I am looking for on ebay before taking things to far apart.

I am going to try to post a video of what I see but I can not seem to record it on the right plane. Operator error.

 

Not sure this video will play but it was worth a shot.

 

None of that will help?
You have found the problem. Remove the seat and figure out what needs to be done. Until the seat is removed you just won't know?
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That is where I was also. Heading to store to get some torx. I had not needed them until now.

Thank you.

 

What is the trick for disconnect the seat power connectors. There are three in a row but I do not see a release clip.

 

Never mind. I got them!

 

Yes they are a bit fiddly for sure!
Those plugs are attached to the bottom of the seat with a small metal blade arraignment. Don't let them hang after you reconnect them. I see this very commonly and they need to be held up and out of the way so they don't get hung on the seat while it's being adjusted.
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So I got into the seat and found what I think is the problem. The mechanism in the picture which raises and lowers the seat does not freely move. The gears mesh well and move in the aluminum housing well. But I am having issue with how to take apart the far end. There is a torx at the end of the shaft in second picture which does not show well. But I can not turn it with out clamping on the shaft. I can but the motor back in but was concerned about damaging something, a gear or the shaft. Any thoughts on how to loosen this?

 

A small diameter "strap wrench" perhaps...?

 

Good job getting that part out! Was not that easy either.
I think I would be looking at getting a used part if I could not figure out anyway to repair mine?
Might be cheaper to see if you can pickup an entire assembly? I see some on EBay that might work?
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I already ordered a used part with a motor. I broke two torx bits trying to loosen up the end. I tried heat, penetrating oil and can not get the screw free. Even if I could get it disassembled I have no idea what might be there in the way of damage. Could be scored, rusted, or who knows what. I do not that I do not have a die for acme threads.

I hope to have the part Tuesday. Fingers crossed that it is a good part.

 

So the part showed up yesterday, I torn into the box like a kid on christmas day. The adjuster moved freely and then I saw it! It was for the right side seat not the left. I have written the guy on ebay ( nomaparts ) for the one he advertised but not heard back. I pointed out to him that there is a L or R on the casting and hope that he really has one.

Does anyone know a good place to get this part?

If I knew how to take apart the shaft and gear I might do that but I get the feeling as if they are pressed on.

 

What bad luck! Yes lets hope the seller has the other side. It's the drivers side so naturally that side will have a lot more use and wear than the passenger side. It's a shame you can't rob the passenger side part and install what you need on the drivers side?

I don't know how that comes apart either? Maybe get your Dremel tool out and start cutting the drivers side apart until you can figure out what to change?
Do you have a grinder and welder? It's looks like that might be required on this repair?
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The guy never responded to me asking if he had the otherside. He is supposed to accept the return however. As it turns out he did have a whole seat bottom which has the part. A lot more money but I need it and have a buyer for the car. So I am back to waiting.

As far as disassembly, I have no need to try now.

 

So the seat frame came with the gears and motors. I got the parts in place in the early evening. My garage was in the mid 90s but I decided to put the seat in.

This is where my mistake happened. I did not check if the left side seat rail for the back had cleared the door jam and scratched it up bad. Some of the scraping is to bare steel. So my near perfect Paint is very scared.

The power will be connected later today. Hopefully the original problem will be fixed. New motor and a free worm gear. I now have some extra motors and gears.

 

The car is back together and the everything worked. Spare motors anyone or drive piece for a driver seat, reach out.

Now to try to polish out the door jam and take the car out for a ride.

Thank you