Dear gents,

I've tried long and hard to solve this issue and it seems that I'm going to need some help on this one before I do any more harm than good
Mind you, I'm an aerospace mechanic, so this is quite embarrassing.

I'm posting a full troubleshoot for future people to find this thread and figure this out more easily next time.
For guys simply looking to help, my question is at the bottom of this post.


I've been using Hayne's Service Repair manual to solve this issue.

The problem:
The issue started about a year ago on my 97 Audi A4 B5.
At first it was no more than the left turn signal lights (driver sits left) staying on (not flashing, just on) after I locked the doors using the remote, this would be resolved by unlocking the doors and relocking. As time went by, it would take more and more attempts of unlocking-locking to get the turn signal unstuck.
Sometimes I left my hazard ligths on for prolonged durations as parking space is scarce in my neighborhood and I would park my car in front of someone's garage doors. I noticed that the cabin of the car would fill with a mild but noticeable electric burn smell.

Since April, the car sleeps more often in a moist underground parking. It's used very scarcely at a rate of once a month, only for some private runs, as I operate a company car.
And now, the car's left turning lights would stay on no matter what I do, and if try to turn the hazard lights on
It's already cost me a new battery, which I replaced as it got depleted beyond recovery.

The local Audi dealers would charge me crazy amounts of money for repairs (menhours paid at 50GBP/hour) so I decided to take matters into own hands.
Using Hayne's wiring diagram, I decided to embark on the troubleshooting journey.

The troubleshooting:
1.I started removing the hazard light switch. But first I wanted to see what was releasing all the burning smell and whether it was related to the left turn signal staying on. So I connected the battery and started playing with the relay. The relay switch is ill-positioned and its hard to see if there is any corrosion on it. By poking it with my screwdriver, I may have shorted something as 2 of the 3 red indicator leds on the front of the unit stopped working.
I removed the hazard light switch completely, and was marveled to see that the left turn signal would stay on. The connector looked ok so unlikely that it was a short coming from there.

2.So I started suspecting the left turn signal. At this point I wasn't accustomed to the wiring diagram yet, so I didn't know that the left turn signal switch behind the wheel gets its power from the hazard light switch . Considering all it would take to remove the unit, I decided to call it a day and to study the wiring diagram.

3a. The next day, I started fresh and having figured Hayne's wiring diagram out, it showed that electrical input can come from 2 sources: the hazard light switch or the central locking module. I realized that I could isolate the fault by pulling the fuses, so decided to pull the 2 fuses (2 and 39) giving power to the the hazard light switched. Connected the battery, and the turn signal lights come and stay on.

3b. So that leaves the central locking module. The module has 2 regular fuses (6 and 14) and one alarm fuse but I also saw that it could bypass those fuses to get power through the ignition switch.

So I pulled the 2 regular fuses, nothing.
The alarm fuse, though indicated on the diagram, I had no idea where it would be. So I decided to rule out the "bypass" source, ie the ignition switch. I gained access to the central locking module (thanks google for indicating me its location, which is in the boot, in the aft right corner), disconnected all the connectors, connected the battery. The turn signal lights are on.

4. With all simple options depleted, and the alarm fuse impossible to find, I decided to have a look under the steering wheel to see if I could find an isolated fuse of 15A connected with red wires, which would be how the alarm fuse is shown on the diagram. I found one module of 3 fuses, of which the middle one was 15A and it was connected by 2 red wires. I pulled it, connected the battery, and miracle, the left turn signal stayed off!
I connected the hazard light switch, however now I notice that though all the lights come on correctly, all turn signals don't flash any more. So I probably shorted something on the hazard light switch in the first step, or is it related to me pulling the fuse? I think that it's the former, so I ordered a used hazard light switch on Ebay and it's on its way. I would need to replace it anyway, given the burn smell.
5. So now, I would like to ask some help. My Hayne's manual won't indicate where I can find the alarm module that powers this turn signal. It says "go see a VAG guy". The plan is to disconnect that wire, so that I can put the fuse back in and operate the alarm, obviously without the left turn signal lights (which I don't mind). I don't need to open it, as I need a quick fix to have something that works and unless they changed wire colours (for the purpose of security) I should be looking for a black and white wire.

So guys, please help me locate this module


I also noticed an electric ticking noise in the front engine, slightly to the right off the center the engine compartment (to the left left when looking from the front of the car) from somewhere between the engine and the airflow meter but deeper down, when I turn the ignition key to the on position (not start). While the heating plugs lights goes off, this ticking sounds keeps going and it doesn't sound healthy. What could it be? Is it bad or is this normal?