Thread: Advice needed.....electric seat controls

AFAIR you prise out the rockers and then be prepared for several springs and ball bearings to pop out all over the place.

AFAIR, the switches are the same as Mercedes switches of that era.

The non operation is usually caused by grease and grime blocking the contacts and you may be able to get them to work by spraying lots of electrical contact cleaner through them.
Regards Philip A

Phillip, did you mean trying to run cleaner through the switches etc prior to popping and distributing bits all around the country, or is that not possible? I'm about to look closely at mine (which I haven't done yet, hence the question). Cheers Gavin

G'day fellas,
Thankyou Phil, your advice was very helpful! I managed to get the switch casing apart with breaking anything OR losing any of the tiny springs and balls inside!!
Miracles DO happen!!
I'll post a photo of the inside of the switch to show where everything goes immediately prior to putting the switch back together.....

Just as you said, Phil, the tops of the switches prise off the tops of the switch posts to allow the top of the switch housing to be separated from the body. Once that's off, you can see inside to two philips head screw that undo to allow the switch assembly to be removed from the body of the switch housing. Working through the underside of the outer housing, under the switch, you have to use a flat bladed screwdriver to gently lever the switch up through the top of the housing as the switch is a push fit over the posts that the two philips head screws go into.

Unfortunately, my switch turned out to be quite clean inside. I pulled it all apart anyway, and cleaned all the brass contacts just to be sure, and pulled the "1", "2", and green buttons out as they were a bit gummed up and not moving freely.
I put it all together and tested it on the seat.......nothing.
I found the relays for the front seats.....swapped them over as the left seat works fine. Still nothing. I checked the square 4 pin plug for power.....yep, the relay is definitely getting power as far as the plug.
I'm now thinking that the silver box mounted up under the driver's seat is some sort of control box that stores the settings for the memory functions. Would that be correct?
Are these known to fail, or perhaps partially fail, and render one seat inoperative?
Cheers
Steve

Yes , although I have never had one with power seats I understand there is a battery in there that dies and corrodes the circuit board.

There have been some AULRO posts on this in years past.
Regards Philip A
Here is one
94 Classic LSE seat computer , Google that term

Bingo!! Now I'm getting somewhere.
Yes, Philip.....I keep forgetting how wonderful google can be. How did we EVER get by without it!!
I found a thread on this site, and I also found a page from the UK where the guy details exactly the problem you mention.
This morning I had no idea that there was an ECU for the seats, lol. So I pulled mine out and opened it up and bingo.....there's a problem, if not THE problem. The NiCad battery has let go, pickling a few bits and bobs around it. The guy from the UK page says that you can replace the battery with a NiMh, replace any damaged components in the vicinity and off you go.
That sure beats shelling out something like A$1800 for a brand new one

Wow the circuit is completely burnt away. Your going to need a picture of an undamaged one to re-create the wiring from (just run fine wires to re-crreate the burnt away tracks). Throw the battery away. if you loose the seat memories each time the battery is disconnect ed ........................ What cares

seeya,
Shane L.

I just had a look on line....the NiMh batteries are only about $30. I dare say I'd be able to get one at Jaycar, as well as any components that have been fried.
I googled PC Board repairs in the Brisbane area and came up with one that's recommended, so I'll give them a call tomorrow and see what they say. I might have to wait until the New Year to be able to contact them but that's not a problem.
I'm optimistic that there's a way to restore full functionality, even if it means sourcing a unit that's not so badly damaged, and then getting the NiMh battery replacement done to extend the life of it. Looking at the one I've got, there are possibly 3 fried chips, a few resistors (?) and then the damage to the tracks.
Either way, it seems I've found the source of the problem.