power seat, mirrors and memory fix
Rennlist Member
Joined: Jul 2002
Posts: 3,269
Likes: 5
From: Deep in the Heart of Texas!
Good post. Makes me wonder why my forward and backward switch sometimes goes to sleep ... do the switch instructions have to go through the controller board on the way to the motors? Worth it to flip the seat over and try reflowing the solder one nice spring day ... might even wake up the snoozing lumbar up and down adjustment ...
Basic Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
Joined: Jan 2003
Posts: 16,940
Likes: 1,038
From: Double Oak, TX
Tom I guarantee that is the problem - all go through the memory box.
__________________
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Addict
Rennlist Member
Rennlist Member
Joined: Sep 2010
Posts: 13,583
Likes: 1,044
From: Boulder Creek, CA
Fantastic. My seats either work fully, or not at all, independent of each other.
Pass seat on a warm day, drivers seat hasnt worked in a year+ at all, but used to only function on warm days as well.
Sitting in the sead oddly..to put pressure in some places more than others USED to work to a degree..reflowing solder makes sense.
Pass seat on a warm day, drivers seat hasnt worked in a year+ at all, but used to only function on warm days as well.
Sitting in the sead oddly..to put pressure in some places more than others USED to work to a degree..reflowing solder makes sense.
Addict
Rennlist Member
Rennlist Member
Joined: Jul 2001
Posts: 7,333
Likes: 117
From: Shawnee, KS, USA
I dealt with this same issue today, thinking it was a problem at a connector, but ultimately deciding it was likely bad solder joints in the power seat controller.
Symptoms were:
For the last few months, I suspected (due to the rule "what you touched last is probably what you broke") that symptom #1 above was due to something I messed up when doing the yellow #1/#2/#3 switch backlighting / incandescent memory switch backlighting -- to clear LED / red LED conversion. I had explored that a couple times before and found nothing.
Today, I spent a lot of time jiggling cables around (first with the seat in the car, and later with the seat removed) and couldn't pinpoint where the discontinuities were occurring. Finally, I noticed that just tapping the power seat control unit would cause the intermittent behavior to change (start working or stop working).
Did you know that the cable to the seat is just long enough to let you test it outside the car?
Got the power seat control unit (928.618.134.02) off the seat (disconnecting all the connectors takes a while!) and opened it up.
As you can see from above, connector #1 is for power and ground (terminals 30, 15, 31). Let's take a look at the solder joints for those pins:
Well, those are crappy solder joints! No wonder there was intermittent power loss!
Repaired those; here's the "after" photo:
And how about that intermittent backlighting on memory switch #1? Here's what the solder joints for the pins for connector #15 (which, with labels like "PL1", "PL2", "PL3", "PT", and "WL" sure looked likely to be related to the switch backlights; "PL1" is probably the switch #1 backlight, and that corresponds to the bottom right pad below) looked like:
Fixed those, too. Went ahead and re-flowed all the rest of the connector pin joints. Most of the rest didn't look so bad.
FWIW, I was using a temperature-controlled soldering iron at 750 °F and added just a little bit of old 60%/40% tin/lead solder (the latter based on the assumption that this old PCB was probably using similar solder) to each joint, mostly for the benefit of adding a little rosin to assist with flow.
IMHO, these PCBs were likely improperly manufactured.
Oh yeah... everything worked perfectly upon seat re-installation.
Symptoms were:
- Seat/mirror memory switch #1 backlighting worked only intermittently.
- Sometimes all three memory switch back-lights would turn off. I only realized yesterday that the power seat motors also were inoperative when this happened.
For the last few months, I suspected (due to the rule "what you touched last is probably what you broke") that symptom #1 above was due to something I messed up when doing the yellow #1/#2/#3 switch backlighting / incandescent memory switch backlighting -- to clear LED / red LED conversion. I had explored that a couple times before and found nothing.
Today, I spent a lot of time jiggling cables around (first with the seat in the car, and later with the seat removed) and couldn't pinpoint where the discontinuities were occurring. Finally, I noticed that just tapping the power seat control unit would cause the intermittent behavior to change (start working or stop working).
Did you know that the cable to the seat is just long enough to let you test it outside the car?
Got the power seat control unit (928.618.134.02) off the seat (disconnecting all the connectors takes a while!) and opened it up.
As you can see from above, connector #1 is for power and ground (terminals 30, 15, 31). Let's take a look at the solder joints for those pins:
Well, those are crappy solder joints! No wonder there was intermittent power loss!
Repaired those; here's the "after" photo:
And how about that intermittent backlighting on memory switch #1? Here's what the solder joints for the pins for connector #15 (which, with labels like "PL1", "PL2", "PL3", "PT", and "WL" sure looked likely to be related to the switch backlights; "PL1" is probably the switch #1 backlight, and that corresponds to the bottom right pad below) looked like:
Fixed those, too. Went ahead and re-flowed all the rest of the connector pin joints. Most of the rest didn't look so bad.
FWIW, I was using a temperature-controlled soldering iron at 750 °F and added just a little bit of old 60%/40% tin/lead solder (the latter based on the assumption that this old PCB was probably using similar solder) to each joint, mostly for the benefit of adding a little rosin to assist with flow.
IMHO, these PCBs were likely improperly manufactured.
Oh yeah... everything worked perfectly upon seat re-installation.
Last edited by Ed Scherer; Apr 14, 2017 at 03:04 PM.
Intermediate
Joined: Oct 2022
Posts: 30
Likes: 1
From: St Catharine's Ontario Canada
I dealt with this same issue today, thinking it was a problem at a connector, but ultimately deciding it was likely bad solder joints in the power seat controller.
Symptoms were:
For the last few months, I suspected (due to the rule "what you touched last is probably what you broke") that symptom #1 above was due to something I messed up when doing the yellow #1/#2/#3 switch backlighting / incandescent memory switch backlighting -- to clear LED / red LED conversion. I had explored that a couple times before and found nothing.
Today, I spent a lot of time jiggling cables around (first with the seat in the car, and later with the seat removed) and couldn't pinpoint where the discontinuities were occurring. Finally, I noticed that just tapping the power seat control unit would cause the intermittent behavior to change (start working or stop working).
Did you know that the cable to the seat is just long enough to let you test it outside the car?
Got the power seat control unit (928.618.134.02) off the seat (disconnecting all the connectors takes a while!) and opened it up.
As you can see from above, connector #1 is for power and ground (terminals 30, 15, 31). Let's take a look at the solder joints for those pins:
Well, those are crappy solder joints! No wonder there was intermittent power loss!
Repaired those; here's the "after" photo:
And how about that intermittent backlighting on memory switch #1? Here's what the solder joints for the pins for connector #15 (which, with labels like "PL1", "PL2", "PL3", "PT", and "WL" sure looked likely to be related to the switch backlights; "PL1" is probably the switch #1 backlight, and that corresponds to the bottom right pad below) looked like:
Fixed those, too. Went ahead and re-flowed all the rest of the connector pin joints. Most of the rest didn't look so bad.
FWIW, I was using a temperature-controlled soldering iron at 750 °F and added just a little bit of old 60%/40% tin/lead solder (the latter based on the assumption that this old PCB was probably using similar solder) to each joint, mostly for the benefit of adding a little rosin to assist with flow.
IMHO, these PCBs were likely improperly manufactured.
Oh yeah... everything worked perfectly upon seat re-installation.
Symptoms were:
- Seat/mirror memory switch #1 backlighting worked only intermittently.
- Sometimes all three memory switch back-lights would turn off. I only realized yesterday that the power seat motors also were inoperative when this happened.
For the last few months, I suspected (due to the rule "what you touched last is probably what you broke") that symptom #1 above was due to something I messed up when doing the yellow #1/#2/#3 switch backlighting / incandescent memory switch backlighting -- to clear LED / red LED conversion. I had explored that a couple times before and found nothing.
Today, I spent a lot of time jiggling cables around (first with the seat in the car, and later with the seat removed) and couldn't pinpoint where the discontinuities were occurring. Finally, I noticed that just tapping the power seat control unit would cause the intermittent behavior to change (start working or stop working).
Did you know that the cable to the seat is just long enough to let you test it outside the car?
Got the power seat control unit (928.618.134.02) off the seat (disconnecting all the connectors takes a while!) and opened it up.
As you can see from above, connector #1 is for power and ground (terminals 30, 15, 31). Let's take a look at the solder joints for those pins:
Well, those are crappy solder joints! No wonder there was intermittent power loss!
Repaired those; here's the "after" photo:
And how about that intermittent backlighting on memory switch #1? Here's what the solder joints for the pins for connector #15 (which, with labels like "PL1", "PL2", "PL3", "PT", and "WL" sure looked likely to be related to the switch backlights; "PL1" is probably the switch #1 backlight, and that corresponds to the bottom right pad below) looked like:
Fixed those, too. Went ahead and re-flowed all the rest of the connector pin joints. Most of the rest didn't look so bad.
FWIW, I was using a temperature-controlled soldering iron at 750 °F and added just a little bit of old 60%/40% tin/lead solder (the latter based on the assumption that this old PCB was probably using similar solder) to each joint, mostly for the benefit of adding a little rosin to assist with flow.
IMHO, these PCBs were likely improperly manufactured.
Oh yeah... everything worked perfectly upon seat re-installation.
Know this is an old thread...just hope there is someone out there reading it..lol
