boxerfan-rooster 2-Adam Mowafy input!

[SoDak]

I have already posted about my alarm problem with a 1991 100 FWD. My passeger side front door lock broke this winter (common problem)and then the alarm would activate when I turned off the ignition. After playing with the broken door lock it returned to normal, and then after a while it returned. I just had the door lock replaced and the same problem remains, the audi dealership is scratching their heads and want to replace the alarm in the central locking systym (big bucks) because they think there is a short in the system. I went to Chris Miller's web site and found a very detailed explanation of what to do to replace & making sure the alarm switch is calibrated (toothed wheel)to the new lock. I copied this off for the dealership in hopes this would help as they are only into the newer audi problems. The two mechanics have 20 & 25 years with audi, but to me seems lacking in this problem! What do you long time audiforum experts think. Thanks

[rooster 2]

I have only had an 86, now have an 87, both did not have alarm systems, so I am no alarm expert.

My thoughts are, since your problem originated with the broken door lock, I have to think that is still the source of your problem. If you haven't done so, use a volt/ohm meter to check the alarm wiring for proper voltage and ground, then observe the mechanical linkage at that door lock that activates/deactivates the alarm system for problems. I suspect that you may find a broken wire or something mechanical (like that tooth wheel)is out of adjustment, and therefore affect the performance of the alarm system.

Audi mechanics are like most mechanics, they don't necessarily have the patience to track down electrical problems. It is always easier for them to replace an entire system to fix it, but at great cost to you. Too often, that is how those guys operate.

If you can't fix it yourself, it makes a lot of sense on a car approaching 20 years old, to just permanetly deactivate the system by pulling the fuse. Car break-ins on old Audis don't happen much any more. Just learn to not leave expensive items in plain site on the seats, that would invite a break-in when parking in a high crime area.

[Kneale Brownson]

The stamped metal replacement lock operating arm they used to replace the broken potmetal operating arm has geared teeth that interact with teeth on the alarm module. However, the teeth on the lever and the teeth on the alarm thingy have two teeth in the center that are only half depth, meaning they won't mesh unless they're aligned properly. And if the teeth don't mesh right, you can't install the circlip that holds in the lock barrel. So if the lock is working, the lever arm has to be aligned correctly with the alarm thingy. However, since the whole system operates off of wires that pass through the driver doorjamb, I'd guess that you have an issue with broken wires in the doorjamb.

[Eric NY]

I would suspect the alarm sensor alignment. Really a PITA to replace the cyl assy and the tooth engagement has to be perfect. This does neccesitate removing the window frame assy, not difficult once you've done it a few times!

Don't believe the audi 100 makes the top twenty most stolen, if it requires much more attention i'd agree with deactivating the alarm!

My 2 cents!

Eric

[Adam Mowafy]

However, The alarm on my V8 is a big pain in the ***. Anytime you want to start the car you have to insert the key in the door and turn it to the unlock poisition. If you open the door before trying to start the car you have to repeat the process. Oy.......


Let us know what you find out.

Audi/Vw alarms always seem to be quirky. I've had two Jetta's and they both had tempermental alarm systems

[SoDak]

Pulling the fuse deactivates the whole system (central locking), so this is out of the question. I still believe it is in the alarm switch on the replaced lock. The reason I believe this is because if I jiggle the key in the lock I hear the alarm horn sound without the system even locking, which makes me think it is not aligned properly. Also if I get the alarm horn to sound this way, and then open the door the alarm will go off and I cannot turn it off by turning the key in this lock, I have to go to the drivers door and turn the alarm off.
My daughter drives this car, and carries alot of color guard flags, since these flags are to long for the trunk we need the locking capability of the car.

[Bisqueth]

ptch

[Kneale Brownson]

What horn does the central locking system use? Is it the vehicle horn or some other horn that could be unplugged? Even if it's the vehicle horn, I've driven months without a horn because the old ones quit and I didn't get around to sourcing and then replacing with new ones. How often do you toot your horn? I think maybe twice in the last month I prompted someone to go on the green arrow. Don't think I used the horn for maybe two or three months before that. Anymore, a horn toot can cause more trouble than it's worth.

[boxerfan]

- Door hinge wires are always suspect unless you have already repaired them.
- iirc the removal of the alarm can be done using a special jumper in place of the starter lockout relay as well as removing the alarm fuse.
- I have experienced what Adam spoke of with a V8 alarm requiring correct synchronization of the alarm and door locks. I think this happened after the battery was disconnected.
- Personally, i think that when things like this break it is not worth my time to repair them. AC, alarm, windows, locks... untikl absolutely necessary I will leave them until the last minute. I have to repair my driver's side door latch/trigger on the '88. It has been that way since about March. Don't sweat the small stuff.
- I leave my car unlocked because anything I have in there is cheaper to replace than filing insurance claims that include a broken window.
- The alignment of the toothed gears for the alarm switch is interesting. Since your issues started with a failed door lock I would certainly start there. I always start by verifying I didn't break anything where I last tinkered.