Hi

I am new to this forum and have read alot of information on the top operation and central locking.

We were given this car BECAUSE it has issues...

1) drivers door lock will unlock driver and passenger door BUT will not turn off alarm, passenger door and trunk lock do turn off alarm

2) convertable top. goes half way up, and compartment lid lifts 3 inches and then squeel from hydraulic pump( sounds like floid bypassing or presure relief), then nothing.

Have redone both trunk sides trunk wiring harness(wires were broken) and pump oil level ok.

3) trunk lid will not unlock with key, got trunk open through opening in ski compartment and long extention.

There is only power going to the trunk lock motor when the key is in lock position. Took actuator apart and can make it operate when power is applied to it

As an after thought the trunk compartment light only turns on when the trunk is open AND the key is in the ignition.

From the previous threads ive read it seems that I cannot do much more without taking it to a dealer or someone with a VAG to get the codes or am I missing something here. I can see the trunk not wanting to unlock if it thinks the top is not secure and also the convertable top dash light flashes.

Any help with these issues would be appreciated.


Steve

 

Steve,
You have multiple issues that you should try to separate as much as possible. Central Locking first. The drivers door unlocks the passenger door because turning the key manually actuates a rod to the Master Actuator to the central locking system. This actuator pneumatically unlocks the other door and the gas filler door. (Check that out to see that it does open the filler door). So that part of it is working OK. Bravo on getting the trunk unlocked as that is one tough operation. Fix that lock. It should open manually as the key turns a rod to open it. You may have a simple problem of the striker plate out of adjustment or it is binding. Also look to see that the Trunk Lid Locking Motor is somehow not binding or jamming the operation of the key lock. When the manual trunk lock issue is fixed, move on to the electrical components of the central locking system. The control module is called the Central Locking/Alarm System/Interior Light Delay Control Module. For some reason at the driver door lock you are not electrically talking to the control module. That sounds like a wiring or switch issue. I'd work on that, and that means opening up the door. However, there is one thing that I would do first. Spend $45 and replace the ignition switch. Get it at the dealership, not an aftermarket!! The control module does interact with the ignition switch and the comment about the key needing to be in is a red flag. The ignition switch is a known weak point and produces many bizzare symptoms. It is an easy fix. Save the convertible top for later, after the central locking issue is fixed. If you need diagrams, PM me.

 

Hi thanks for the reply

Yes the fuel door does open
The problem of the trunk lock it that if I have the actuator out, as it is now, I can lock and unlock the trunk no problem, if the actuator is installed though, once the doors are locked the actuator does not unlock so the tab on the lock cylinder isnt shifted over causing the lock cylinder push button to not contact the release cam.

As far as ign switch I will start there as I have noticed it doesnt have a good feel to it when rotating it and also the odd time it will momentarly activate the power windows....

I have spent at least 8 hours on this and I do alot of automotive electrical on domestic autos (G.M. tech) but Audi is leaving me stressed everytime I look at it....

 

"Also look to see that the Trunk Lid Locking Motor is somehow not binding or jamming the operation of the key lock."

Bingo. Well done Hub. However, I disagree that these are unrelated issues. Here's why:

OP - Your trunk issue? I'll take it one step further. Funny enough, it has to do with the wiring to your power antenna. The yellow "keyed hot" wire, specifically. When I replaced my antenna mast and motor, the antenna extended immediately upon starting the car. The radio didn't turn on... just the antenna. What the Hell? Turning the radio on and off didn't do anything. The antenna mast just stayed sticking up. So I turned off the car, and whaddayaknow. The damned thing went down.

Turns out, I had a short between the yellow "keyed hot" wire and the blue "accessory" wire, in the driver's side trunk loom running to the antenna motor. The blue "accessory" basically just fires 12 volts when the stereo is turned on, which triggers a switch in the antenna motor. When that blue wire is "hot," the switch tells the motor to raise the antenna. When the blue wire drops voltage (when you turn off the stereo), the switch draws current to the motor again, but this time in order to lower the antenna... even when you shut down and jump out of the car right away. Because all the while, the power for the motor itself is always there, supplied by the "constant hot" red wire.

Short version?

12 volts is 12 volts in a car. When your antenna's blue lead gets 12 volts from the stereo turning on, the antenna goes up. Which means, my antenna didn't care if the stereo was on or off. The blue wire was getting 12 volts whenever the key was in the ignition of my car, because the yellow wire threw 12 volts into the blue short. Taking the key out killed the yellow wire voltage, finally cutting the 12 volts running through the short and sending the antenna down.

What does this mean to you? Simply put, every wire has its purpose, and it's that way for a reason.

I'm thinking that your yellow and red wires have been switched somewhere along your driver's side trunk loom. That's the only scenario to explain your trunk light only working when you have the key in. Think about it... You obviously have the key OUT OF THE IGNITION when you're using it IN THE DOOR LOCK, and having your issues.

If my theory is correct:
1) the trunk light has NO POWER when you're unlocking the door.
2) the trunk lock has no power when you're unlocking the door.
3) YOUR ALARM has no power when you're unlocking the door.

What else do these three items have in common? They are three of the four items supplied with power from the red "constant hot" wire located immediately upstream of the fourth item which is, you guessed it... your power antenna. Your other powered items on the back end of the car, like brake lights and your top? That red "constant hot" supply wire is on the passenger side.

So tell me two things... First, how is your antenna working right now? Correctly? Or, like my car, did the previous owner install a crappy aftermarket setup right before he sold it to you? Second, with the key in the ignition and the car running, does using your spare key in the driver's door now actually lock/unlock your trunk? I have a feeling it will. This should also theoretically re-align the trunk-lock mechanism, allowing you to use the key to lock/unlock the trunk.

Here's the best part!!! The re-alignment of your trunk-lock mechanism should (again, theoretically) eliminate your convertible top problem, too! The '94 uses a trunk-lock alignment microswitch to determine whether it will allow/disallow the RAISING OF YOUR TONNEAU PAST THE THREE-INCH POINT. This is to keep the tonneau from powering up into your raised trunk lid by accident.

If it doesn't work, You have an air bubble in the pump's hydraulic supply line. You need to bleed the air out like you do when you bleed brakes.

If you discover that I am correct, and the driver's side trunk loom's yellow and red wires are crossed, I subsequently proclaim my diagnostic kung-fu to be ridiculously strong, and furthermore declare myself a frickin' HERO.

If not, well f@ck it. You get what you paid for, and my monitor isn't spitting cash at me for this.

 

Welll..... now that you mention it.....
The car has aftermarket radio AND I had a battery drain overnight so...after removing fuses to locate the current draw I found the power antenna to be the draw, I have it unpluged right now.

So are you saying the wired may be shorted to each other OR is the aftermarket radio (no idea whem it was installed) causing the problem?

Steve

 

do these cars have alarms from the factory? please say no...i have had my car for 6 years, and no alarm here...I too have a battery draw, if my car sits for close to 2 weeks..the battery dies.

 

You're close, Steve.

I think it's more likely that the person who wired the aftermarket antenna did it incorrectly. Somewhere on the left side of your trunk, probably within a foot of your antenna, the wires were cut to do an install, and then spliced back together wrong.

Something back there was once wired yellow "keyed hot" and was re-wired red "constant hot" by the amateur who doesn't know what the yellow wire was actually for... Keep in mind, if the car wasn't running when they did whatever work they did, there would be no voltage from the yellow... the installation of aftermarket stereo equipment has messed up a LOT of B4's over the years.

If this is the case, you might have 2 problems. The yellow wire is now hanging, and possibly shorting to the negatively grounded frame of the car. Also, you sound like you have some electrical device that no longer fully powers down when you turn the car off, because it is now wired "constant hot," or more literally, "constant ON."

Is this making sense? I know I have a tendency to ramble. I'm doing my best to keep it concise on this reply.

And imncrxtc, peel the carpet off the inner left wall of the trunk. If there's a 4" diameter black plastic car horn back there, you have a factory alarm.

 

I was too tired to explore the electrical issue but you motivated me. The trunk light on the '94 gets its ground through the Trunk Lid Closed Position Switch. Trunk is open, light gets grounded, light comes on. Power comes through the S14, 5 amp fuse. I'm having trouble tracing how the fuse is powered, but a great test to confirm the wire cross/short would be to remove the S14 fuse. If the trunk light operates as you have described, you know something is not right. Page 17 in the '94 wiring diagram. I'm holding off on any more thoughts until the ignition switch is replaced. Remove the plastic fairing around the steering wheel near the instrument cluster, and the two screws going into the cluster, and slide the cluster out. Warpage of the dash can be problematic, but the cluster will come out. Tip it out of the way or disconnect it. Two tiny allen screws hold in the electrical portion of the switch. They may be covered with locktite or red paint. Loosen them but do not remove them or they will be lost forever. The switch slides out. Do not try to reinvent the wheel. This is the only way to get at the switch. By the way, the hyd pump is suppossed to be self bleeding. Also, I've spent hours acquiring parts and working on that powered antenna to keep it stock, just to avoid the problems described. Happy Thanksgiving.

 

Thanks to both of you for your reply

Yes it does have a factory alarm, it does not look like someone has cut the factory wiring to the power antenna but I will look further, I do know there is 3 conectors on the trunk by the antenna, one for the antenna , one single wire with a very small conector and 1 I cant remember what it looks like,

I am going to get a ignition switch today anyhow as it just doesnt seem to feel right and with the key on(ignition) seems to only take a slight rotation to the left to turn it off.

The prev owner stated he thought all of the symptoms started at the same time but I did not think to ask about the stereo install.

Again thanks for both your time and knowledge and I will let you know more after I do some checking

 

Hi again

Ok replaced ign switch- same issues

I checked the power antenna,it is factory, 1 wire has constant power (red) and one has power when radio turned on, there is also a single wire by the antenna with a red conector and it wasnt hooked up to anything-(key on power). Antenna is stoped part way up and relay inside it clicks when I plug it in- So faulty antenna

Now the odd thing is.... there is no power to the trunk light without the key in ignition. If I take out fuse S19...I still have trunk light when key is on and trunk latch is open, also other items on the same circuit work as well....keep in mind that this a car built for Canada so it has daytime running lights as well if that makes a difference.