Trroubles with central locking

[LittleEcker]

Another clueless youngin with a question here

So I somewhat recently got my first e30 (1991 318is) and the driver's side lock cylinder would jam when trying to lock the car (typical). So after I took apart the door and replaced the lock cylinder and ONLY the lock cylinder. Now, when I go to the trunk and try to unlock the car, it unlocks after I turn the key 90 degrees, as opposed to 180. Then, when I turn it back upright, it locks, and then immediately unlocks, as if it jumps back over or something. I must have done something wrong, but I have no idea what it could be. Any ideas?

Also, I don't know if these two things correlate, but the battery has been dying a lot recently, since I don't get to drive it much (yet), so I have been disconnecting the battery pretty frequently.

Any help or idea is appreciated. Thanks!

[butters]

Also, I don't know if these two things correlate, but the battery has been dying a lot recently, since I don't get to drive it much (yet), so I have been disconnecting the battery pretty frequently.

I have had the same experience. When the battery is dying or lacking charge, the locks do not function properly.

[LittleEcker]

Help us out e30 wizards!

[butters]

What I meant is that this is likely a normal symptom of low voltage. Get a new battery and then you can determine if you have a real problem.

With a good charge my locks returned to normal functionality. My car has been parked most of the winter as well, and I could tell right away that the battery was dead if the central locking acted up. After driving awhile the issue went away.

I wound up replacing my battery, it was old anyway. The point is, with voltage as an unknown variable you may be chasing your tail.

[LittleEcker]

Well the battery has been low for a while, but it only started after I took the door apart. I got it to stop briefly, but then I drove around a little and it started up again. I can try charging the battery up (since it's relatively new) again, but I don't think that's the problem. How would that relate to low battery levels?

[StereoInstaller1]

There is a chance that your door lock system is killing your battery.

If an actualor is stuck half way, the system will continue to attempt to lock.

Go look at the ETM, pull the central lock fuse, wait 24 hours, see if battery health is better.

Luke

[LittleEcker]

Could you elaborate? Cause the battery has been "draining" pretty quickly.

Also, you're gonna have to talk dumb with me. I'm 15.

[StereoInstaller1]

Eh, you don't seem dumb to me.

So the little motor that lock and unlocks the door is called an "Actuator".

If the actuator is all old and nasty and sort of stuck, the motor will keep trying to move the lock...draining your battery.

Do a little googling, find the "ETM" (Electrical Training Manual" for your car. Download and study, you will see how everything is like little maps. Some understand immediately, most never do, don't be harsh if it makes no sense...but do find out which fuse you need to remove to take power from the "Central Locking relay Module"

GL
Luke

[LittleEcker]

Well both doors jump back to unlocked once I lock it. Does that mean I should check both actuators?

[StereoInstaller1]

It means they are fucked one way or another, pull the fuse and see if that is the issue.

[dogsbark26]

The locks are designed to "jump back" like that when there is a fault in the system. It could be almost anything: a door not closed properly, a sticking actuator, an electrical fault...
Do what StereoInstaller1 says. He knows.

[LittleEcker]

Alright I'll give it a look. Thanks guys!

I'll let you know if I need more help.

[Butler]

This thread just sparked my interest to fix my central locking, again. When mine "died" it suddenly started locking and unlocking rapidly while driving down the road. It lasted for about 20 seconds before it stopped on its own. It's been broken ever since.

I did the red wire door loop with no luck. I'm going to double check my work and proceed to purchase a new central locking unit as long as that's the next step.