Door Locks
05-04-2003, 09:01 PM
#1
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Door Locks
Today, several members of the Detroit area got together to work on a couple of cars that are going to SITM. All went well with the exception of my door locks. Dave and I (more Dave) disassembled the drivers door to replace the door handle actuator. When we went to reassemble the locking mechanism, we found that the power locks would not cycle. When we turned the two hex bolts lose the motor mount, there would be a slight pop and then the motor would work. After working on this for about 5 hours, our eyes could not tell between the setup on another car and the one on my car. Any suggestions?
Ell
Ell
05-04-2003, 10:59 PM
#3
928 Engine Re-Re-Rebuild Specialist
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Yeah, there are strips of skin missing from the backs of my hands now.
To add to the symptoms:
The lock cylinder, both using the key and turning the inside dial, do not seem to turn as easily or smoothly as they should, each having resistance before actually turning.
John.....let's see you use those new fangled computer skills and post this afternoon's picture!
To add to the symptoms:
The lock cylinder, both using the key and turning the inside dial, do not seem to turn as easily or smoothly as they should, each having resistance before actually turning.
John.....let's see you use those new fangled computer skills and post this afternoon's picture!
05-05-2003, 01:16 AM
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You guys have the same trouble I have...
A few years ago, I had a problem with one of the door locks. I bought a replacement from one of the big three, and since then I've had nothing but trouble from them.
The part I bought was new- the troubles come from the fact that these door lock servos are VERY VERY sensitive to how they are mounted.
The way they work is fascinating. They are VERY similar to the servos in model airplanes- in fact, on more than one occasion, I've thought of emailing Futaba or Airtronics and describing what I have and what I want...perhaps they have something superior. But of course, reality steps in and I realize that it is not my natural position in the grand scheme to re-engineer Porsche's model 928~
Basically, the two motors talk to one another. If they are not adjusted exactly perfectly, then when one reaches the end of its travel and stops...it realizes that the other is NOT at the end of its travel and comes to the conclusion that the owner of the car has decided to move the locks to the opposite postion...so it begins moving in the OPPOSITE direction.
Thus they can cycle back and forth...mine do this incessantly! Recently I took the door panels off, pulled the servos, and following the manuals TO THE LETTER ...set them the way they are supposed to be. Great. I put all that effort into the car...and when I was done- they would sit there and cycle for a minute, and in the end they would not unlock the passenger door when I unlocked my side! My girlfriend came to town a day later...and the looks on her face said it all~
Model airplane servos have a thing known as a "pot". This is simply an electronic part that measures the travel of the servo arm, and stops the servo's motor when it reaches the desired position. Basically, when you send a command to a model plane in flight, a radio signal from the transmitter is decoded by the onboard receiver and turned into digital information that is passed on to the servo. This is simply in the form of "move the arm to position X". The motor starts, and stops when it reaches that point. The pot tells the servo motor when this has happened. I think the servos in our doors have a pot as well, and this is where I think my problem [and perhaps yours] exists as well. The arm on the door lock servo has to be set just right...but also the pot. If the pot arm is not in the correct position, then the motor will receive bogus information, and despite the fact that you have the servo mounted perfectly as per the book...it wont work right.
How do you set the servo pot? Heh heh heh!!! I'll pay you damn good money to tell me that-!
I sure haven't figured it out.
I want to find an alarm system that I can hook up to both door servos...then I'll eliminate the f*cking "data link", open my doors remotely...and solve one of my cars biggest problems.
Normy!
'85 S2 5 Speed
A few years ago, I had a problem with one of the door locks. I bought a replacement from one of the big three, and since then I've had nothing but trouble from them.
The part I bought was new- the troubles come from the fact that these door lock servos are VERY VERY sensitive to how they are mounted.
The way they work is fascinating. They are VERY similar to the servos in model airplanes- in fact, on more than one occasion, I've thought of emailing Futaba or Airtronics and describing what I have and what I want...perhaps they have something superior. But of course, reality steps in and I realize that it is not my natural position in the grand scheme to re-engineer Porsche's model 928~
Basically, the two motors talk to one another. If they are not adjusted exactly perfectly, then when one reaches the end of its travel and stops...it realizes that the other is NOT at the end of its travel and comes to the conclusion that the owner of the car has decided to move the locks to the opposite postion...so it begins moving in the OPPOSITE direction.
Thus they can cycle back and forth...mine do this incessantly! Recently I took the door panels off, pulled the servos, and following the manuals TO THE LETTER ...set them the way they are supposed to be. Great. I put all that effort into the car...and when I was done- they would sit there and cycle for a minute, and in the end they would not unlock the passenger door when I unlocked my side! My girlfriend came to town a day later...and the looks on her face said it all~
Model airplane servos have a thing known as a "pot". This is simply an electronic part that measures the travel of the servo arm, and stops the servo's motor when it reaches the desired position. Basically, when you send a command to a model plane in flight, a radio signal from the transmitter is decoded by the onboard receiver and turned into digital information that is passed on to the servo. This is simply in the form of "move the arm to position X". The motor starts, and stops when it reaches that point. The pot tells the servo motor when this has happened. I think the servos in our doors have a pot as well, and this is where I think my problem [and perhaps yours] exists as well. The arm on the door lock servo has to be set just right...but also the pot. If the pot arm is not in the correct position, then the motor will receive bogus information, and despite the fact that you have the servo mounted perfectly as per the book...it wont work right.
How do you set the servo pot? Heh heh heh!!! I'll pay you damn good money to tell me that-!
I sure haven't figured it out.
I want to find an alarm system that I can hook up to both door servos...then I'll eliminate the f*cking "data link", open my doors remotely...and solve one of my cars biggest problems.
Normy!
'85 S2 5 Speed
05-05-2003, 10:49 AM
#7
Racer
I've go the later model locks, and they don't work either. In case anyone has some thoughts, I've been wrestling with this for quite a while. I have the electronic central locking brain (which does work). The position switches in the key cyclinders work aon all three locks, but I cannot get the lock solenoids to fire at all (they don't even click or twitch in either door) Neither the key cyclinders nor the button on the dash can get them to work.
HELP!!!
HELP!!!
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05-05-2003, 04:04 PM
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The lock servos are actually very simple. They consist of a 12 vdc motor driving a gear reduction unit. There are three wires - battery voltage, ground and switched voltage.
Inside the gearbox, there is a copper disk that turns with the output shaft. This disk has a pie-slice shaped wedge cut out of the copper.
There are a couple of small brushes that ride on the copper disk. One brush is attached to the battery power line, so it always has 12 vdc. This brush normally sits in the cut-out portion of the disk, so no voltage flows. The other brush, which always touches the copper on the disk, is attached to the motor.
When the motor receives a short pulse of 12 vdc on the signal line, the motor starts running. The pulse will make it run long enough for the battery voltage brush to get off of the cutout onto the copper disk. This will keep the motor running until the brush gets to the cutout again, at which point the motor receives no power and stops.
At least it is supposed to stop. If the motor and gearbox run very freely, the flywheel effect of the motor can make it coast just enough for the power brush to touch the copper disk again - and you are off and running, over and over.
One possible fix is to disassemble the gearbox and pack it with soft, sticky grease, which will add enough drag to prevent the overrun.
Another possible fix is to make the cut-out in the copper disk just a little bigger.
Another possibility is to put a resistor in the power line to slow the motor down just enough to prevent the overrunning condition. I haven't tried this one, but it should work. I would start with a low resistance (perhaps 4 or 5 ohms, whatever is available) 5-watt power resistor, and go from there.
If you can prevent the overrun, the adjustment might be a lot easier.
Inside the gearbox, there is a copper disk that turns with the output shaft. This disk has a pie-slice shaped wedge cut out of the copper.
There are a couple of small brushes that ride on the copper disk. One brush is attached to the battery power line, so it always has 12 vdc. This brush normally sits in the cut-out portion of the disk, so no voltage flows. The other brush, which always touches the copper on the disk, is attached to the motor.
When the motor receives a short pulse of 12 vdc on the signal line, the motor starts running. The pulse will make it run long enough for the battery voltage brush to get off of the cutout onto the copper disk. This will keep the motor running until the brush gets to the cutout again, at which point the motor receives no power and stops.
At least it is supposed to stop. If the motor and gearbox run very freely, the flywheel effect of the motor can make it coast just enough for the power brush to touch the copper disk again - and you are off and running, over and over.
One possible fix is to disassemble the gearbox and pack it with soft, sticky grease, which will add enough drag to prevent the overrun.
Another possible fix is to make the cut-out in the copper disk just a little bigger.
Another possibility is to put a resistor in the power line to slow the motor down just enough to prevent the overrunning condition. I haven't tried this one, but it should work. I would start with a low resistance (perhaps 4 or 5 ohms, whatever is available) 5-watt power resistor, and go from there.
If you can prevent the overrun, the adjustment might be a lot easier.
05-05-2003, 04:10 PM
#9
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Wally,
I think what is happening is that there is an adjustment problem. If one of the brackets are tightened down securely, the lock cylinder binds. If you loosen it, the binding is less noticeable. Then the locks do operate intermittently I believe.
Is this correct Dave?
I think what is happening is that there is an adjustment problem. If one of the brackets are tightened down securely, the lock cylinder binds. If you loosen it, the binding is less noticeable. Then the locks do operate intermittently I believe.
Is this correct Dave?
05-05-2003, 05:45 PM
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by WallyP:
<strong>When the motor receives a short pulse of 12 vdc on the signal line, the motor starts running. At least it is supposed to stop. If the motor and gearbox run very freely,</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">------
Hello,
Wally made as usual a great explanation of the electrical function of the system - But there is also a mechanical side 'of the story'.
quote:
When the motor receives a short pulse of 12 vdc on the signal line, the motor starts running.
---
The same happen when you open the door manually with the key, or you touch the turning handle or the up/down pin - The motor will start - Also the same will happen if the mechanical parts is not running free - If you e.g. turn the big plastic nuts to hard, or get other friction some how in the lock unit - or if the motor is not placed so the rod from the lock to the motor is totally free (when the motor stops) and therefore pushing on the motor handle - I.e. Wally's cobber brush will be connected and the motor runs and runs for ever
That'S like a puzzle to fix this.
Good luck with the puzzle <img border="0" alt="[byebye]" title="" src="graemlins/wave.gif" />
<strong>When the motor receives a short pulse of 12 vdc on the signal line, the motor starts running. At least it is supposed to stop. If the motor and gearbox run very freely,</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">------
Hello,
Wally made as usual a great explanation of the electrical function of the system - But there is also a mechanical side 'of the story'.
quote:
When the motor receives a short pulse of 12 vdc on the signal line, the motor starts running.
---
The same happen when you open the door manually with the key, or you touch the turning handle or the up/down pin - The motor will start - Also the same will happen if the mechanical parts is not running free - If you e.g. turn the big plastic nuts to hard, or get other friction some how in the lock unit - or if the motor is not placed so the rod from the lock to the motor is totally free (when the motor stops) and therefore pushing on the motor handle - I.e. Wally's cobber brush will be connected and the motor runs and runs for ever
That'S like a puzzle to fix this.
Good luck with the puzzle <img border="0" alt="[byebye]" title="" src="graemlins/wave.gif" />
05-05-2003, 05:55 PM
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Doz is correct that the lock will not cycle when everything is tightened down. It will cycle halfway on the first attempt and then nothing.
The motor was not taken apart, nor was the lock cylinder. Just the connecting arms (with their "ball" joints) we taken off and placed back on. Is it possible that these are positioned improperly?
The motor was not taken apart, nor was the lock cylinder. Just the connecting arms (with their "ball" joints) we taken off and placed back on. Is it possible that these are positioned improperly?
05-07-2003, 08:36 AM
#12
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We tried re-aligning the locking mechanisms. It got late so we had to close up the door so that I could get home. However, now the lock moves nice and smooth with the following problems:
The door won't open with the inside handle. Probably an adjustment issue.
The locks don't cycle when using the key or turning the **** on the door. They will work from the central door lock push button on the center console. I am going to pull this apart tonight again and see what I can find. Any input to this would be helpful.
The door won't open with the inside handle. Probably an adjustment issue.
The locks don't cycle when using the key or turning the **** on the door. They will work from the central door lock push button on the center console. I am going to pull this apart tonight again and see what I can find. Any input to this would be helpful.
05-07-2003, 11:06 AM
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Ell:
<strong>
1. The door won't open with the inside handle. Probably an adjustment issue.
2. The locks don't cycle when using the key or turning the **** on the door. </strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">----
Ell,
1. Yes must a question of adjustment
2. I just check on my car - Mine do
Are the **** and the pin moving when you actuated the lock from the central panel?
I think you have to check all the mechanical connections and check they are all fixed correct and mowing smooth
Yes, that's a time consuming puzzle, but take it as a challenge, then one day you will get it to work. -
I have not touch mine for years - At the beginning I 'was there' quite often. - At that time I also installed remote control, anti theft system with start lock and automatic window closing - That was a challenge!
Good luck with the adventure <img border="0" alt="[thumbsup]" title="" src="graemlins/bigok.gif" />
<strong>
1. The door won't open with the inside handle. Probably an adjustment issue.
2. The locks don't cycle when using the key or turning the **** on the door. </strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">----
Ell,
1. Yes must a question of adjustment
2. I just check on my car - Mine do
Are the **** and the pin moving when you actuated the lock from the central panel?
I think you have to check all the mechanical connections and check they are all fixed correct and mowing smooth
Yes, that's a time consuming puzzle, but take it as a challenge, then one day you will get it to work. -
I have not touch mine for years - At the beginning I 'was there' quite often. - At that time I also installed remote control, anti theft system with start lock and automatic window closing - That was a challenge!
Good luck with the adventure <img border="0" alt="[thumbsup]" title="" src="graemlins/bigok.gif" />
05-07-2003, 03:18 PM
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Ell,
The door has an adjustment on the inside of the panel. This will adjust how much or how little the pull is to actuate the striker release.
How was the minor tuneup? Can you tell a difference?
The door has an adjustment on the inside of the panel. This will adjust how much or how little the pull is to actuate the striker release.
How was the minor tuneup? Can you tell a difference?