Drivers Seat No Power

Well, another interesting glitch. Drivers seat has no power. Worked about 2 weeks ago. Now no adjustment of any kind from the power seat switches. Nothing works. Checked all fuses, including E2, E3, E4 and B5. I did check each and every fuse. Outside mirrors work. It truly is a puzzle. Cannot access under the seat to check things out because I cannot move seat fore and aft, or up and down. Took off front seat cover and wiggled all the connectors. Nothing. At least the seat is in its normal position so I could just ignore the problem. But I would like to figure it out. May have to pull the seat switch panel and check that out. But what a PITA with the seat lowered. I've read that running an separate supply voltage to the pins on the seat switch may work the motors fore and aft so I could access the seat bolts underneath. I looked at the wiring diagram for the seat, switch and memory module. No other fuses involved. It is just like it is not getting 12V for anything. Anybody got any ideas to check? Everything looks okay under the seat with the wiring harness. No cut or chaffed wires. Completely stumped.

I also checked the seat memory module for faults with my Durametric. No faults in either memory module. Passenger seat works fine. Go figure.... Memory module wiring:

Does the voltage meter move when you press the buttons?

Nope. No voltage drop. No clicks, no sounds, no clunks. And of course, no movement in any direction. I have 12V on both sides of the fuse, so it must be something between the fuse block and the seat. I may have to make a fancy hooked type of pin to check the voltage, or lack thereof, at the wire connections on the memory module. Just that everything is fairly inaccessible from the front part underneath the seat. BTW, I see that a door contact is wired into the memory module, as well as the backup light contact. Back up lights both work. Seat doesn't work with ignition off, ignition on and engine running, door open or door closed, no movement. When I do the passenger side, everything works with ignition off, ignition on, door open or closed.

I just ordered a clamp voltage/ammeter from Amazon Prime. Non-intrusive wire testing unit, so I should be able to see if I have voltage on that big red wire.

Still stumped and troubleshooting continues. Got the clamp on multimeter and tested the power supply wires to the seat. I have 12V at the Voltage Supply terminals so it is not lack of power. Mirror controls work. Passenger seat works. I guess the next step is to remove the seat switch panel and see what I have there. Hate to think that there may be a problem with the memory seat module that I cannot solve, or have to fork over $1340 for a new one that may or may not solve my problem. The other thing is that in order to get to the seat bolts so I can work underneath the seat, I will have to tear the entire seat bottom out and off the frame. I could leave well enough alone given the seat is in the correct position...but it bugs me that something is wrong and I can't figure out what it is. Someone on another forum thread suggested to try a complete electrical system reset - disconnect both battery leads and connect them together to drain all power from every system in the car. I did that for over thirty minutes....no change to anything.

Not sure if this is applicable or not, but on my old Merc 300 E I had the same problem. After removing seat etc. I decided to take switch apart. All the contacts were corroded enough to not allow voltage through. Case was solved. Cleaned up and presto I have not worked on my Porsche seat switch though. If you live by salt water or not in the south west this may be your problem. Hope this helps...

Two thoughts: First, it is possible to bypass the memory seat module in the electric seats. I swapped a set of seats from a memory module car into my 2000 that originally had manual seats, and all of the electric adjusters work fine without a memory module. This may not be a solution for you, but it could be used to verify that the seat side motors, switches, limit switches, etc are functional. I�d have to dig a little, or try for a photo of my seat, but it is simple, you just need the power and ground leads, some crimp connectors and some wire - the jumpers you need are easy to make. I reused a factory harness plug because I had a spare from old seats, but it isn�t required. Second, you can probably get a memory module for a ton less. My 2002 had racing seats in it when I purchased it, and I needed to reinstall the factory seats (came with the car), but the memory module was shot. I found one on ebay for a couple of hundred bucks that works fine. I think this was the video I used: You Tube

Thanks a million for that. I would love to bypass the memory module, especially just to see if everything works with a direct power supply and ground. I've read up on how to remove the bottom seat cushion to access things with the seat stuck without power. Now I just have to get brave enough to do that. I cannot move the seat to access the seat bolts, so this might prove to be difficult with the seat stuck in the car.

Pulled the seat switch panel. Shot electrical contact cleaner into all the holes....no change. No seat movement in any direction. I got brave and pulled the white pins down and undid the white clamps that hold the bottom seat cushion on the seat frame. I lifted up the bottom seat cushion to access everything underneath. I have power all the way to the seat memory module on both the 30 amp power supply and 7.5 amp memory module circuit, and ground continuity to the under seat grounding point. I'm beginning to believe the seat memory module is fried. I now have access to the two front seat bolts, so I may remove those and run a 12V jumper wire to the appropriate seat module pins for fore/aft movement so I can access the rear seat bolts, or I may create a wiring harness as shown in the video (Thanks!!) to bypass the memory module. Anyway, here are some pictures of where I am.

BTW - Given the mess of wires underneath the seat, and the fact that nothing is zip-tied or secured like normal wiring bundles with either the fabric wrap or electrical tape (that mass of wires is just like that and runs around the end of the seat memory module to the front plugs), I'm wondering if someone has been under there before. Clearly see a problem with that. The power leads are sitting right next to the frame rail and could easily get caught in the gears for fore/aft movement. Just a FWIW

Well, dammit, still confounded and discouraged. I have 12V power to the voltage supply pins on the memory module. So an alternative wiring harness as shown in the video is not going to work because I already have power to the pins on the memory module. Short of trying to bust the memory module out from under the seat with a pry bar, or trying to dismantle the fore/aft motor while working under the seat cushion so I could possibly move the seat in order to remove the back seat bolts...I am truly at a loss as to what to do next. Stopping for today, walked away from it....having a beer.

What a PITA! Worse than coolant tank replacement. Sorry I have no ideas for you. Wonder what the dealership would do?

I asked my wife why if I could figure out the entire USS Denebola (AF-56), USS Truett (DDG-1095) (I was a Machinist Mate in the Navy), the entire drainage system for the San Joaquin valley (I am an Environmental Engineer), Maine Yankee Nuclear power plant (yep, worked in a nuclear power plant), Environmental Engineer for a local government for 13 years (water and wastewater systems design), a Computer Consultant helping numerous local businesses for the last 25 years (solving computer problems and fixing them), why then why can I not figure out a power seat problem? She has absolute trust in me. Yet, totally discouraged with the problem, I'm packing it in today, reassembly of where I'm at and giving up. I hate that. At this point in time, I would rather be replacing my AOS again. Trying to decrypt a Porsche electrical engineer's design of a seat memory module functions and trying to find a way around why it doesn't work apparently is beyond me. Short of breaking parts, using pry bars to bust stuff, or removing motors and gears just to be able to move the seat to access the rear seat bolts in order to remove the seat (what's that going to get me?), I cannot see a way forward. Good luck to the next person who's seat fails. My car will never go to a dealer. Deal was in order to own it, I have to be able to fix it no matter what. This is one fix that isn't going to happen.

Since the seat can�t be raised, could you possibly get a ratcheting wrench, like a gear wrench style, on the seat bolts? I realize they are etorx and that�ll be harder to find, but maybe one of the universal fit deals craftsman has might work? Getting the seat up will make your work easier. I seem to recall being able to access the module from the top after removing those white plastic fasteners (they have a pin arrangement locking them in place) but I can�t swear to it. Seems like the front of the seat cushion hinged upward...

Since you got the seat bottom out and can see the drive motors, should be easy enough to use a battery from a cordless drill and some jumper wires to run the motors. I have used 9v,12v, or even 18v cordless batteries for such things, and have probably had to do just that on seats, but I have had to do so many things like that that I don't have any specific memory of it, or that I am just getting Alzheimers. lol

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DBJoe, reviving this thread. I just posted the pinout in the other thread you asked about it in. The issue is NOT having power to the memory module, you are jumping power and ground directly to the seat switches, so they bypass all of the electrical magic happening inside that big black box.

Yeah...I get that. Like I said in the other thread, the problem is going to be how to access the top of the memory module to do the jump. This is what I have...the seat frame is in the way of plug 5 and 6

You don't need the memory module to be in line. You can disconnect it and just run with the "big black connector" The two end terminals in the bottom picture is where the power comes from