HELP! What does this wire do - with picture

[Ianmeister]

Hi guys

I recently had a wire short on my car whilst driving along in the torrential rain. I lost all power, there was a lot of white smoke and the car wouldn't restart?

The car now restarts but I need to know what caused it. I have traced it to a green wire which has melted all the plastic off. I have taken a picture of where it connects behind the glove box.

Can anyone identify what this wire does and what may have caused the short??

http://photos1.blogger.com/blogger/1057 ... 010017.jpg

Many thanks in advance

[eko]

Brian Moore is the man you need to speak too,sure hell be along soon!

[Ianmeister]

Thanks - any help would be appreciated

In the meantime, I'm going to disconnect it to see what happens

[Sidrick]

White smoke from under the bonnet or inside the cabin?

[Ianmeister]

Inside the cabin

[Sidrick]

The cause seems quite clearly to be a leak somewhere. Have you noticed any moisture or dampness around that area?

[Ianmeister]

I've just checked and fuse 19 has blown. According to Haynes this is for electric mirrors.

My car is a track car and so there is no button for the electric mirrors.

Is this fuse used for anything else?

Does this fuse correlate to the picture of the green wire shown in the first post?

Thanks!

[ian332isport]

That green wire provides a 12v feed from the ignition switch to the central locking control module pin 5.

If you crash the car, there's an inertia switch inside the central locking module that closes and sends an 'unlock request' to unlock any of the doors on impacts of more than 6g. That green wire provides the 12v feed for this.

As far as I can see, there's no fuse in that particular circuit, so any shorts are going to keep smoking until you turn the ignition off. If everything runs okay now, then I assume the wire has either broken/melted or the short has been removed.

Cheers,

Ian.

[ian332isport]

I've just checked and fuse 19 has blown. According to Haynes this is for electric mirrors.

My car is a track car and so there is no button for the electric mirrors.

Is this fuse used for anything else?

Does this fuse correlate to the picture of the green wire shown in the first post?

Thanks!

Fuse 19 also feeds power to the Interior light delay unit (mounts next to the central locking module) as well as the mirrors and the dual temp switch on the radiator (if fitted).

I would say you probably had water ingress down by the central locking module which has somehow shorted across to the interior light delay unit (or it's wiring if the unit is not fitted).

You can find all of this down in the drivers side kickwell below where the speaker would be mounted.

Ian.

[Ianmeister]

That green wire provides a 12v feed from the ignition switch to the central locking control module pin 5.

If you crash the car, there's an inertia switch inside the central locking module that closes and sends an 'unlock request' to unlock any of the doors on impacts of more than 6g. That green wire provides the 12v feed for this.

As far as I can see, there's no fuse in that particular circuit, so any shorts are going to keep smoking until you turn the ignition off. If everything runs okay now, then I assume the wire has either broken/melted or the short has been removed.

Cheers,
Ian.

The car did have a front impact recently, which would explain this.

I have disconnected the connector but the wire has melted itself bare - what would be the best thing to do with it.

[Ianmeister]

Fuse 19 also feeds power to the Interior light delay unit (mounts next to the central locking module) as well as the mirrors and the dual temp switch on the radiator (if fitted).

I would say you probably had water ingress down by the central locking module which has somehow shorted across to the interior light delay unit (or it's wiring if the unit is not fitted).

You can find all of this down in the drivers side kickwell below where the speaker would be mounted.

Ian.

Thanks again.

There was some water ingress in the passenger footwell which as you have said, could have caused the short.

[Ianmeister]

Everything appears to run fine now EXCEPT brake lights are on all the time, and the front indicators don't work (so the other indcators flash double speed).

How could it all be related?

Could the melted wire have caused this as some of the other wires are slightly damaged.

Thanks again ian332isport!!

[Sidrick]

I'd try a 2nd hand fusebox from a scrappy mate. It might save time trying to track down faulty components.

[ian332isport]

what would be the best thing to do with it.

If it's a race car then just unplug it from the connector behind the glovebox and forget about it. You've probably removed the central locking anyway

Everything appears to run fine now EXCEPT brake lights are on all the time, and the front indicators don't work (so the other indcators flash double speed).

How could it all be related?

Could the melted wire have caused this as some of the other wires are slightly damaged.

I suspect the green wire has taken out a few others when it melted. Unfortunately you are going to have to follow the green wire all the way and repair any other melted wires.

Mind you, the indicator problems may be due to the recent front impact rather than the melted wiring.

Cheers,

Ian.

[Brianmoooore]

Been busy all day, but I see Ian's been standing in!
Front indicators quite often don't work after an impact. The front indicators aren't particularly waterproof, and, although the holders don't corrode, the lamps do. The lamps have probably moved slightly in their holders because of the impact and are no longer making contact.
Brake lights - Pull the connector off the switch (top of brake pedal), and see if they go out. If they do, see if the pedal is coming high enough to work the switch. If not, adjust the brake pull rod across the car behind the heater. If the rod is OK, change the switch.
Fuse 19 and the green wire both point towards trouble around the speaker area in the drivers footwell. Look for chaffed wiring.
If this is a track car, the central locking should be disabled. I wouldn't be happy with the possibility that a flailing arm could push the door button down in a crash. As Ian says, the wire is the emergency release for the locking system, so if you don't have central locking it can be removed along with the rest of it's loom (under the carpets) which its probably cooked.
This loom is for the windows as well.

[Ianmeister]

If it's a race car then just unplug it from the connector behind the glovebox and forget about it. You've probably removed the central locking anyway

Yes, central locking is removed - I will unplug the connector behind the glovebox, but is the wire live at either end?

I suspect the green wire has taken out a few others when it melted. Unfortunately you are going to have to follow the green wire all the way and repair any other melted wires.

Mind you, the indicator problems may be due to the recent front impact rather than the melted wiring

I thought that may be the case

Thanks again for the prompt reply

[Ianmeister]

Front indicators quite often don't work after an impact. The front indicators aren't particularly waterproof, and, although the holders don't corrode, the lamps do. The lamps have probably moved slightly in their holders because of the impact and are no longer making contact.

I've replaced the front bumper so hopefully this wouldn't be the case? The indicator that didn't break worked before I replaced the bumper, now it doesn't?

Brake lights - Pull the connector off the switch (top of brake pedal), and see if they go out. If they do, see if the pedal is coming high enough to work the switch. If not, adjust the brake pull rod across the car behind the heater. If the rod is OK, change the switch

Thanks - I'll test this

Fuse 19 and the green wire both point towards trouble around the speaker area in the drivers footwell. Look for chaffed wiring.
If this is a track car, the central locking should be disabled. I wouldn't be happy with the possibility that a flailing arm could push the door button down in a crash. As Ian says, the wire is the emergency release for the locking system, so if you don't have central locking it can be removed along with the rest of it's loom (under the carpets) which its probably cooked.
This loom is for the windows as well

I do still use the electric windows so may not replace the loom altogether. I wouldn't say the loom is cooked but a couple of the wires are slightly damaged. what do the other wires in this loom do?

Thanks for your help - it's really appreciated!

[Brianmoooore]

The loom is joined to the main body loom by just three wires which connect to the drivers door pillar socket. These are red/black (normal feed to the central locking), a green/black wire and a brown.
Cut all the wires from the door pillar socket EXCEPT these three, pull a green/blue wire from the accessories socket and the loom will be dead and can be removed, along with the passenger door socket.
The green/blue usualy goes to a little relay in UKcars, along with a red/yellow wire from the accessories socket as well. This can all come out.