Central locking actuators

ianc · 12-14-2007, 11:59 AM

Hi folks,

To get my doors to lock via central locking, I have to turn the key CW twice. One turn of the key gets the locking button halfway down, and the second pulls it all the way down. This happens on both doors.

I've got one door apart, and the actuator appears to be working fine. The rod is adjusted to the correct 146.5 mm length, it just doesn't have sufficient 'oomph' to pull down the locking mechanism down in one go. I've tried to lubricate all the moving points I can see, but it is spring-loaded, and there is additional friction between the locking knob and the top door trim piece.

Do these actuators just lose their mojo when they're old? I notice when I hold the acuator in my hand that it has full travel when unloaded, but if I hold the piston, it doesn't take very much at all to make it stop midway though its stroke.

Would a new actuator cure this? Has anyone else experienced this? Thanks for any thoughts,

ianc

ianc · 12-15-2007, 09:17 AM

Oy, are mine the only dodgy ones in the world?

Wouldn't surprise me...

ianc

RoninLB · 12-15-2007, 09:33 AM

I don't have your install.

But i did do a stock solenoid lock and rod install hooked up to my Viper so only wild guesses from me.

Since it's common to both actuators/solenoids I'd hook a good 12v source and see if they work full distance that way. Don't remember if the actuators have a plug connector or not but I'd disconnect the solenoid before trying this.

That would be great info to work from imo.

ianc · 12-15-2007, 09:46 AM

Hi Ron,

I think we may be thinking of different things here. There is a microswitch on the back of the lock cylinder (inside the door) which detects when you turn the key and sends a signal to the central-locking 'black box' mounted in the console.

After some indeterminate rigamarole there, a signal gets sent to the actuator, which is like a little sealed electric motor in a plastic case with an integral gearset and actuating arm which bolts to the door. This actuating arm is getting full travel when there is nothing connected to it (when i hold it in my hand), but when hooked up to the locking mechanism in the door, it just doesn't have the juice to move it completely in one cycle of the key.

I don't really know enough about what's going on in the 'black box' to say whether it's a problem with the actuators, or the 'black box' itself. Hoping someone else can chime in with a similar experience.

I was kinda hoping Warren would chime in here, but I just read of his health difficulties this AM, so I'm hoping for the best for him. Take care,

ianc

RoninLB · 12-15-2007, 10:22 AM

can you disconnect wires to the actuator and put a good 12v to it when it's hooked up to the lock?

ianc · 12-16-2007, 08:46 AM

Well, unfortunately it's too late for that because I put the door back together again. I hate taking doors apart.

I would dismantle them again if I was reasonably sure of being able to get them working properly however...

Seems like everybody's central locking is working properly except for mine though. Boohoo...

ianc

dfink · 01-03-2008, 02:18 PM

OK here is what I just did to finally fix my long term lock problem. To clarify doors would unlock fine just not lock. For the first couple of years it appeared to be a loose connection as I could wiggle random wires and things would start working. It then pretty much quit except for an occational attempt to lock that would not succeed. After replacing both door switches, checking every ground and every connector I pulled the control for the must be 10th time to have another look. I finally saw what appeared to be a funky solder connection on the riser board for the pins. Upon closer oberservation I found this was a lifted copper trace that had turned gray and pulled away from the board. I am lucky that a friend has a set of repair manuals so a look at the diagram and I see that the trace runs to pin number 6 which is the power for the lock side of things.
I removed the lifed trace from the daughter board. Drilled a hole through the main board in to the lead trace for the relays. I then ran a wire from this connection to the solder connection for pin 6 and howdy doody I have working locks again.
It sounds similar to your situation in that you are not getting a good enough connection to lock the first time. I would pull the control unit and take a close look at the trace for pin 6. The pins are numbered on the plastic. Hope this helps. Only took me 5 years to find this PITA.

ianc · 01-03-2008, 03:07 PM

Hi dfink,

Thanks for the post.

Quote:

I pulled the control for the must be 10th time to have another look

Here I assume you're talking about the actual controller mounted in the console in front of the gearshift lever?

I'm not so sure I'm having a similar problem to you. Yours sounds like it was behaving flakily and not working sometimes until it finally quit. Mine always works, it just doesn't have the strength to fully pull the locking knob down against the spring tension and friction of the knob against the door top trim.

ianc

dfink · 01-03-2008, 04:39 PM

No, I am talking about the control unit that is in the front right fender well. The unit in the center console does nothing but show the light and completes a ground circuit to the controller when pressed. It is a simple momentary switch.

ianc · 01-03-2008, 09:45 PM

Quote:

No, I am talking about the control unit that is in the front right fender well.

Hmmm... Never even knew the little bugger lived under there. Well... I think I will not investigate that particular lead any further due to the disparities in our symptoms. However, your post will undoubtedly be helpful for some poor schmuck who's having flaky locking problems. Thanks again!

ianc

jonbot · 01-03-2008, 10:20 PM

FWIW, I just finished installing an aftermarket central locking system, and initially it didn't have enough "oomph" to lock and unlock the doors, I also had to click it twice. The system was marginal, sometimes it would close it sometimes it wouldn't. The mechanism in the lock of the door turned out to be dirty and required excess force to move the rod. You can try this as a test, spray some WD40 in the friction points of the lock mechanism in the door, you can spray it in there via the openings on the inner side of the door, if that fixes the problem, then you probably just need to clean and grease the lock mechanism. Thats what I did, and now the central locking system works perfectly. Over time I think the locks just end up losing their lube, and collecting dirt.

Edit: Also lubricate the pivot point behind the round locking knob.

ianc · 01-03-2008, 10:46 PM

Quote:

You can try this as a test, spray some WD40 in the friction points of the lock mechanism in the door

Done it. Lubed everything I could see.

Thing is, that portion of the locking mechanism affected by the actuator is spring-loaded, so the actuator arm must overcome that as well as any linkage friction.

The side I took apart is working a little smoother, but the other is the same. Will probably have to tear into it soon. Like summer.

ianc

dfink · 01-04-2008, 04:42 AM

Quote:

Originally Posted by ianc

Hmmm... Never even knew the little bugger lived under there. Well... I think I will not investigate that particular lead any further due to the disparities in our symptoms. However, your post will undoubtedly be helpful for some poor schmuck who's having flaky locking problems. Thanks again!

ianc

Just so you know the unit in the center console is not really a control unit. It is only a momentary switch with a couple of resistors and LEDs. The resistors simply adjust the brightness of the LED. The actual control unit is the one I mentioned in the right front fender. It is located behind the hood hinge next to the windshield antenna box. One small nut (wrench size 10mm) on a stud holds the unit in. Only a couple of minutes to take it out check and clean the leads and put it back. You could have mechanical resistance but I bet it is more likely electrical resistance that is keeping your system from working. Especially if they unlock with ease.