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Discussion Starter · #1 ·
You fix one thing and someones law says it will be something else. Sometimes the central locking works on the hatchback (tailgate) and sometimes it doesn`t. Now it hasn`t worked for 3 weeks, the drivers door and passenger door are fine. So where do I start with this one? The wiring on the motor? Bentley says the common earth point is by the handbrake but if was that then the rest of it wouldn`t work, would it?
Bentley also advises NOT applying an outside power source to the motor to test it, so am I right in thinking my first step is to see if I`m actually getting juice to the motor?

thanks in advance for all responses,

Les
 

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Remove the hatch inner panel. Watch the action of the lock motor (while your assistant operates the door lock button). You can apply power for testing purposes, but don't apply it for more than 1/2 second. Don't operate it too much or it will overheat, let it cool for a minute after you've cycled it 10 times.
Usually you can see that a simple adjustment is needed. In some cases the motor locks or unlocks with enough force that it "bounces" back to its previous position.
I've had good luck using a lot of sticky grease on the mechanism to stop the bounce.
 

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les 900T16S said:
Sometimes the central locking works on the hatchback (tailgate) and sometimes it doesn`t. Now it hasn`t worked for 3 weeks, the drivers door and passenger door are fine. So where do I start with this one?
I'd start by checking continuity of the wire between locking control unit and lock on the tailgate, I think. Mebbe it's fractured where it flexes as the tailgate opens and closes.
 

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sometimes mine wont work at all, not even the passenger door. It varies everytime I get in car...autolocks when getting out to drop something in the mail, and when I get back it won't auto lock, but generally the hatch and door work (or dont together). Also, everynow and then the little bar that connects the hatch handle to the inside mechanism will fall out or pop loose...a big hassle when you have a big armfull of something and have to climb back there and get it from the inside. But as far as the central locking...I have no clue but wish it would work.
-Alex

edit: as for your hatch, just take a look inside (1st u should be able to at least hear the motor if it works with out even opening the hatch.) If you hear it, chances are something just came loose, its a very simple system, and I can offer pictures if you would like.
 

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Discussion Starter · #6 ·
Thanks for the tips so far guys. I don`t have juice going to the hatch. Seems a bit unlikely that both wires have flexed sufficient to break so I`m going to try to have a look at the connections further forward.

Three questions.-

1) Where does the wiring go when it`s gone through to the main car body at the hatch hinge?

2) Where exactly is this control unit under the right hand side of the dash. I can`t see any gaps at all. How far towards the pedals? Where laterally in relation to steering wheel?

3) Bentley has a picture of part 75 which it says is a distribution block in the right side wheel arch area. Why isn`t it in the circuit diagram?

Thanks again

Les
 

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les 900T16S said:
2) Where exactly is this control unit under the right hand side of the dash.
I thought it was the passenger side on a RHD car? Might be under the driver's side on a left-hooker, but didn't get moved for RHD. That's the biggest issue with Bentley, it doesn't try to cope with non-US cars, which it seems can differ quite a bit.

3) Bentley has a picture of part 75 which it says is a distribution block in the right side wheel arch area. Why isn`t it in the circuit diagram?
That's the plastic block with the big red wires going into it, right? IIRC that's on the battery side of the fusebox, so outside the scope of the individual circuit diagrams.
 

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les 900T16S said:
Bentley has a picture of part 75 which it says is a distribution block in the right side wheel arch area. Why isn`t it in the circuit diagram?
It is, in the factory manual.
 

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same problem, I can't find the controller under either side. Does someone have a picture of where it is? I'm taking it off a 4dr, will it make a difference?
-Alex

give me a few minutes and I'll snap a few shots and someone car draw arrows to where it is?
 

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Well all I could find is the video camera so these pics are most likely garbage. The 1st 2 are of the left hand drivers side. The 3rd is the right hand passenger side. The top in all of the pictures is the "knee board" thing.






 

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Discussion Starter · #11 ·
Still stuck with this guys, can I check out a couple more points before considering taking the car to bits,

1) If I connect up a 12 volt DC supply, one side to earth and the other a half second burst to the motor , once on each wire depending on its position open or locked, that should operate the motor-correct?

2) If the passenger door motor works ok then terminals 7 and 8 on the control box thing must be ok- correct?

3) If I connect a voltmeter across earth and one of the wires to the tailgate and operate the key in the drivers door then if the wiring is ok I should get a "flash" of 12 volts- correct?

Or have I completely misunderstood the way this system works?

Perhaps I should add its a 1988 Turbo 16 S, UK model

thanks for your patience,

Les
 

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Discussion Starter · #12 ·
Still stuck with this help please

I`m still stuck with this, anyone help with the last questions please

thanks for looking guys,

Les
 

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les 900T16S said:
1) If I connect up a 12 volt DC supply, one side to earth and the other a half second burst to the motor , once on each wire depending on its position open or locked, that should operate the motor-correct?
Should do, yes.

+ve to one terminal, earth to other will lock if unlocked.
Swap connections over, will unlock if locked.

2) If the passenger door motor works ok then terminals 7 and 8 on the control box thing must be ok- correct?
Yep. The tailgate/bootlid/rear doors should work at the same time, too.

Pins 1 & 2 are earthed by the key being turned either way in the driver's door lock - so earthing pins 1 and 2 in turn should fire off the lock/unlock, too.

3) If I connect a voltmeter across earth and one of the wires to the tailgate and operate the key in the drivers door then if the wiring is ok I should get a "flash" of 12 volts- correct?
+12v one way, -12v t'other.

Or have I completely misunderstood the way this system works?
Looks about right to me, going from the Bentley wiring diagram.

I may well have a rummage at this on mine over the weekend. SWMBO's busy, and the weather looks good.
 

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can u hear c/l boot unit working?? a friend of mine (called les) had same problem with his ruby boot, all it was, was that the connecting rod from the actuator had come of the plastic conection(broke up, knackered)that operated the release mechanism so we connected it back together and put a nylon tie across the joint to hold it in place no problems since.it did work without the tie, but eventually it would have come adrift again due to the broken/perished plastic bit. can u get them, no idea??. about the 4-5 mm in size. 4 litle plastic legs/ keeps, and one had broken so other part dropped off. just a case of a bit of crappy plastic f888888 it up
 

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TooMany2cvs said:
les 900T16S said:
1) If I connect up a 12 volt DC supply, one side to earth and the other a half second burst to the motor , once on each wire depending on its position open or locked, that should operate the motor-correct?
Should do, yes.
Just looking at this before I get stuck in to mine in a minute, Bentley's quite vocal NOT to "bench test" the motors by live feeding them. May well burn them out.

I have no idea if the risk is real, but the letters "CAUTION" are quite persuasive...
 

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just rip all the powerlock stuff out and save yourself a few lbs...its not like its overly hard to lock/unlock the pas. door or the hatch...
 

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TooMany2cvs said:
Just looking at this before I get stuck in to mine in a minute, Bentley's quite vocal NOT to "bench test" the motors by live feeding them. May well burn them out.
Dunno about that, but putting a live to pin 7 blew the fuse...

Anyway - getting to the box is dead easy. *RHD*
Stick your head in the passenger footwell, and undo the single torx screw holding the lower dash vent up.
Lower it slightly, and slide the metal bracket you can see off.
That's the central locking box, attached to the bracket.

Pin 4 should be +12v
Pin 3 should be a good earth.
With the driver's door locked, pin 1 should be earthed
With the driver's door unlocked, pin 2 should be earthed.
You should not have both 1 and 2 earthed simultaneously.

Unfortunately, I don't seem to have anything being put out on pins 7 or 8. They should be fed +ve voltage for half a second when the earthing changes from pin 1 to 2 and vice versa. They aren't. There's good continuity from the box pins to the passenger door shut multiplug.

Duff control box? Gotta be, hasn't it?
 

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TooMany2cvs said:
...then throw your good locking box my way!
if you werent across the pond i would throw you one or two. anything unnecessary always comes out on my cars :lol:
 
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