Rear Hatch unlock R&R
 

As I have been redoing MadDog I have also been fixing the bits and pieces that have not worked in years. So it was the hatch locking mechanism's turn.
The system is reasonably (and surprisingly for 951) uncomplicated.
Consists of 2 pan head screws in the hatch, that are held in the down and locked position by 2 ring style locks that can expand to let the screw in and then lock around it. To unlock using either key or the unlocking motor, the operation is the same, a twist of the mechanism pushes 2 rods out towards the lock rings and they expand releasing the hatch.
See pics:

http://forums.pelicanparts.com/uploa...1536232159.jpg

http://forums.pelicanparts.com/uploa...1536232159.jpg

http://forums.pelicanparts.com/uploa...1536232159.jpg

http://forums.pelicanparts.com/uploa...1536232159.jpg

The failure mode is either it won't lock, or won't unlock. It can also lock/unlock one side only.

To trouble shoot/fix, first make sure that the lock ring/s expand and contract freely with the key being used to unlock (will get to the motor driven process later).
If rings are frozen or sluggish use WD-40 on the lube points shown and also into the little well the rings live in.
Manipulate the mechanism to where it moves freely and you can see the rings expand and contract.
After the above make sure the length of the pan heads is correct to get them deep enough into the rings to lock, but not so long as to be loose. I adjusted mine to where I have to use a firm down wards pressure on the hatch to lock it, and it does not have any motion/play after it locks.
Once the system works with the key we can now move to the electric unlock.

The motor (shown above) drives a gear mechanism which pulls the lock mechanism via a 'Z' shaped lever attached to a pull cable. When the motor rotates the cable is pulled (unlocking) and when the motor returns home position it allows the mechanism to lock.
On mine the lever and the cable attachment were broken, I had removed them some time ago to fix and did not get back to them.
The lever is available from Pelican and other sources....but it costs 130.00 bucks. I did not price the cable.
Will continue next post, apologies about the text in the pic hope it is legible with zoom, if not will redo.
Sox

I have this stuff I am about to put up for sale, including the cable.

$15 bucks shipped and it's yours...

https://s26.postimg.cc/u0dvb6ep5/IMG..._063325256.jpg

Keith just a bit too late :( I already rebuilt it.
Thanks.

So to continue....
I built a drive lever from a piece of steel stock I had lying around.

http://forums.pelicanparts.com/uploa...1536253187.jpg

The cable was shredded

http://forums.pelicanparts.com/uploa...1536253262.jpg

Welded an attach point to the motor drive lever to pull the cable with.

http://forums.pelicanparts.com/uploa...1536253330.jpg

Old sheath without the cable in it.

http://forums.pelicanparts.com/uploa...1536253442.jpg

Cut the cable off from the 'Eye' in the push drive mechanism.

http://forums.pelicanparts.com/uploa...1536253548.jpg

Cut a thread on the 'eye' to put a threaded aluminum piece to hold the cable to the 'eye'

http://forums.pelicanparts.com/uploa...1536253641.jpg

http://forums.pelicanparts.com/uploa...1536253641.jpg

Source of new cable.

http://forums.pelicanparts.com/uploa...1536253729.jpg

Inserted the cable attached it and crimped it.

http://forums.pelicanparts.com/uploa...1536253782.jpg

to be continued hit the 10 pic limit.
Sox

Ok upwards and onward...

http://forums.pelicanparts.com/uploa...1536253947.jpg

Installation on the car is pretty straight forward. Remember the 'C' , it is a pain to put back on when you have to do it looking upside down into the hatch.

http://forums.pelicanparts.com/uploa...1536254074.jpg

http://forums.pelicanparts.com/uploa...1536254074.jpg

Now for the easy part :)
the electrical stuff.
The Motor is actuated by power sent to it from the switch in the floor well. This is the red/white wire.
The brown wire is the return to Gnd.
The motor rotates and the lever pulls the braided cable and releases the locks.
When the switch is released the power in the red wire (always on) returns the motor to 'home' which is the locked position.
The white wire is the 'home' return wire.
See pic

http://forums.pelicanparts.com/uploa...1536254404.jpg

Issues:
1) fuse #11 15amp blown.
2 ) Bad switch.
3) Bad motor.

If any one like me to further post on the above 3 will do so.
Sox

One thing I found on this latest 944 of mine is that the screws on the electric motor itself that hold the magnetic portion in place over the armature windings can come loose and even fall out.

This causes the magnet to shift and contact the armature, preventing the motor from functioning. If the motor is in the "return home" mode, it will drain your battery and heat up the motor.

Another thing to look at if your hatch release button doesn't work and you have some mysterious current drainage going on.

Ask me how I know....

Sox,
Just excellent. I appreciate all the time you took to post the pics and write ups.
So far mine works, but I'm bookmarking this post and dropping in the Porsche folderhttp://forums.pelicanparts.com/suppo...eys/wolfie.gifhttp://forums.pelicanparts.com/suppo...eys/wolfie.gif

Thanks Bruce...just a little payback for all the help everyone on this forum gives me.

Keith, the tail gate motor has a thermal relay to disconnect the motor after a little time, so it should not have been running (or trying to) and drain the battery .
Sox

http://forums.pelicanparts.com/uploa...1536439275.jpg