Car is beeping when boot open

[Johnbu]

Car started doing something odd today.

The dashboard makes a long beep every 5 secs or so when the boot is open.

When you open the driver's door it stops.

Doesn't stop with passenger door open.

It's a 3 door GTI.

Also, if use the key to unlock only the boot and the open the boot, there is a fast mechanical noise coming from the passenger side taillights. Sounds like a relay, similar to lock unlocking.

If you unlock the car (doors and boot), there is no mechanical noise from the passenger side taillights.

Never encountered this before and I've had the car for 10 years.

I know a low battery can give all sorts of issues/false warnings etc, but it doesn't seem like a battery issue.

Any ideas?




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[Johnbu]

Update, more cryptic clues.

With the boot partially open, the boot light works and no beeping.

With the boot fully open, the boot light turns off and I get the beeping.

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[saabman]

Sounds like issues with the wiring to the bolt lid.

If possible get a VCDS scan. It should point to particular faulty bits.

You may find the rear demister also doesn’t work. Check for blown fuses in the fuse box in the side of the dash. Don’t replace the blown fuse till you find the actual fault.
The wiring harness is on the passenger side visible when you open the boot lid.
The insulation goes hard then cracks and shorts out and/or the wire now bends on a smaller arc and snaps.
I found I needed to remove the plastic trim from the boot lid to get good access to the wire, even then it a a bit tight. Pull the rubber boot back and unwind the cloth tape. The damage will become evident.

[Johnbu]

Sounds like issues with the wiring to the bolt lid.

Thank you. You're 100% correct.

I had a play with the wiring and it works (light) when I wiggle the wiring to boot lid.

I'll take it apart this weekend.

[saabman]

Good luck with it.

While it maybe tempting to just rejoin the wires. While it’s a lot more work I added a new length of wire so the joins are in the body and in the boot lid where they don’t flex.

There is a lot of wires in there some of them are rather thin as well.

[maltbbe]

I had to deal with this when my brake lights stopped working. There's not a lot of room to work, but I soldered some extra lengths of wire into all the wires in the harness that were split; seems to have held up so far.

[Johnbu]

I had to deal with this when my brake lights stopped working. There's not a lot of room to work, but I soldered some extra lengths of wire into all the wires in the harness that were split; seems to have held up so far.

An update,

I fixed it by soldering extra wire to the broken wires which fixed the issue but I think I will have more issues in future as lots of other wires appear to be cracking too.

Let's hope they dont break in the near future.

Can't believe VW would use so much guage wire.

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[saabman]

I think it’s not so much the gauge of wire - though it does look awefully thin a lot of it. I think the issue is more to do with the insulation is going hard and brittle so it’s breaking that then causes the copper to bend on a much smaller radius and subsequently breaking.

[Johnbu]

You're correct.

However perhaps more wires would resist breaking the wire.

Anyway, it seems like a poor deisgn.

Just a matter of time before I need to replace the other wires.

The odd thing is why are there so many cables that need to go into the boot lid?





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[JustCruisn]

The odd thing is why are there so many cables that need to go into the boot lid?

Off the top of my head:
high brake light
wiper
defroster
radio aerial
Reverse light
Fog light
Badge pop for camera
camera wires

[saabman]

add to that its two sepperate aerial wires,
and the interior boot light switch line.