Help please with electrical/mechanical issue

[1781cc]

I had to be towed home by the AA the other day as my starter motor disintegrated, it's probably the original one from the car so it's done ok, but when the garage took the car in and explored the replacement they found that it has an aluminium rod connecting the steering to the starter that causes a part of the electrical engagement process, it's been stuck for what appears to be ages and is bent, they have tried Audi for a replacement but it's on back order with no date in sight.

This could be the cause of my electrical leak, as if it's bent it can allow the key out and dash lights off but the starter motor remains charged, it's the same part that locks the gearbox in park via cable.

Any suggestions on sourcing this part or work around to delete this part of the chain if a part is no longer available?

Thanks

[Ben]

I'm confused by your description (or it could be the Irish whiskey I've been supping all night)

The bit that doesn't allow the key out of the lock unless you are in park has no physical connection to the starter motor. The gear selector lever is locked into park until you press the brake pedal which energises a solenoid to release the gear lever. Is the rod you are talking about in this picture?: http://www.partsbase.org/audi/audi-cabriolet-aca-eu-1995-71310-selector-mechanism/

[1781cc]

Hi, thanks for the reply, if my description is funny it's because I don't understand it properly myself, it's to do with a connection from the ignition barrel to the starter motor, it's a mechanical rod rather than purely electrical.

As it was explained to me, when the car is parked and you take the key out, it locks the gear selector in place, so even if you put your foot on the pedal you still can't take it out of gear.

So when you put the key in, and turn the steering lock a little while turning the key, the steering lock releases, the gear selector releases and the rod pre-arms the starter motor, a further turn of the car sends the electrical charge to actually engage the starter

The reverse of which is when you park, put the gears into P, turn the key off, and lock the wheel, my rod is apparently bent and it keeps a pre-engage charge running to the starter even though by then the key is out and the dash lights are off.

Overnight it means I come back to a flat battery in the morning

[Hanuman]

I'm with Ben, and I think that either the description you received is wrong, or your understanding of it.*

There is to my knowledge No Mechanical Connection between starter motor and steering lock.
What you actually have is 'shift lock' which is pictured above.

You can should only be able to start an automatic with it in Park or Neutral. (Certainly in 2 of my V8s, the Park position doesn't always go into Park if the gear selector was pushed to gently). This is all because of starter solenoid lockouts.

With shift lock, you cannot remove the ignition key if the gear selector is not in park. You will see that when you turn the key anti clockwise to off, it doesn't quite move far enough until you place the gear selector in park. Now you can remove the key.
If you turn the ignition off with the gear selector in neutral, you cannot remove the key.
It's a security function of sorts. With the key removed, it takes a lot of work to move the car as the transmission is locked.

Once the gear selector is in park, you cannot move the selector out of park unless you press the brake pedal. It's a safety measure of sorts- most folks with automatics park the car with the gear selector, and the handbrake is never set. If you could go straight from park to drive without a brake set, the car could move unintentionally.

Here is the ignition lock/steering lock


And in Ben's diagram above, item 42 is a cable that links the gear selector to the ignition lock. That cable moves a lever on the top of the steering lock, which stops the key from being removed if the gear selector is not mechanically in the right position- Park.

Electrically, there are a few issues, as my V8 project keeps giving me.
The car must also detect that the gear selector is in either Park or Neutral to start. Otherwise, the starter won't work. As I mentioned, if the gear selector is not pushed positively into park, the indication on the instruments is that the gear lever is still in another gear. Reverse.

Another mechanical problem, which is where you might be having a problem, is that after starting the engine, the key doesn't always return to the run position properly. This has left me with the starter still engaged with the engine running. After a little investigation, I believe this is related to the ignition lock barrel, rather than the 'shiftlock'. However, I've not had time to look into this any further.

*of course- my understanding of all this might be flawed, too!

[Ben]

Originally Posted by 1781cc

my rod is apparently bent and it keeps a pre-engage charge running to the starter even though by then the key is out and the dash lights are off.

Overnight it means I come back to a flat battery in the morning

I'm thinking they are saying that something in the interlock system is bent that's not allowing the ignition switch to be in the fully off position with the key removed, allowing something to still be powered, it shouldn't be the starter motor though. The last thing powered on the ignition switch before pulling the key out is part off the courtesy light circuit. When you pull the key, it removes the 12v from the small terminal on the ign switch, triggering the courtesy light timer relay. Does your courtesy light come on when you pull the key?

One way off checking is to unplug the plug from the back of the ignition switch overnight to see if the battery goes flat.

[1781cc]

Yup, My understanding of it was wrong, this is the part we have had to replace:

8A0 905 851 B

Ignition Lock/Starter Switch, it basically was bent in a way that it allowed you to pull the key but wasn't killing the power so there was a drain, obviously this being jammed was affecting how the starter motor was disengaged once the car was running.

Hopefully this gets to the bottom of the power issue and with the new start motor I will be back on the road!

Thanks for the guidance, I couldn't get my head around the "rod" explanation