Alarm going off, internal lights staying on

[Spendare]

Hi everyone, thought I'd post on here rather than the FB page - always preferred a forum!

Hoping to get some advice on why my alarm keeps going off. It's a highline model, so factory fitted sensors and it seems ok if I turn these off. There's no bugs living in the van but in last few days the tailgate hasn't released properly a couple of times and I've need to manually release it by taking the plug off above the lock inside and pushing the lever in there.

After reading lots on here and other websites, I'm coming to the conclusion the microswitch on the tailgate is duff or at least on it's way out. I've leapt to this as one test I read was to see if the internal lights come on/ go when you open doors. I've checked this and the internal lights don't off when I shut and lock the doors. This might have been happening for a while as I recall them staying on and I ended up leaving the lights in the always off setting.

The van can be locked for 24+ hours before the alarm goes off, or it can go off after a few hours of being locked (with sensors on) so it's quite random.

I've been plagued with electrical problems ever since the van was converted in Jan, the conversion company added new rear speakers in the tailgate but used screws way too long and they pieced the loose speakers wires causing it to ground out and burn my stereo out, plus flatten the battery. I've since added a new stereo and starter battery, but since adding the battery, I've had this alarm issue. VW wouldn't code the new battery in as it didn't have a QR code on there for them they also said they couldn't get any fault codes on why the alarm was going off.

Would appreciate any feedback, the van is going into VW on Thursday as the oil filter they fitted is leaking, so if there's a chance it's the microswitch, I can get them to change that also. Seems howeverI need to tell them the problem rather than let them work it out themselves

 

[Big Al]

They should be able to see the measured values `live` as they operate the lock/handle so then they can make a decision surely. I had an issue with side door lock.. my fault was the interior lock/un-lock switch was inop. but central locking worked fine. New lock sorted under warranty thankfully!

 

[Spendare]

The vans been into VW, they have replaced the tailgate latch and microswitch as there was a fault showing there.
Seems there's still a problem though, they were seeing the interior lights come on about 30 secs after locking the van up.
I got the van home and while the lights didn't come on 30 secs after, they did come on a few hours later, on their own - this set the alarm off again
Seems there's a small power drain on the main battery also, it's loosing about 0.1v every few hours.

The conversion company added some internal reading lights to the rear when it went back to them - if they've wired these into the wrong circuit could it be causing a drain and for the lights to come on, over their own accord?

Trying a process of elimination at the moment, current got it locked with the internal lights turned off to see if alarm still goes off.
Am tempted to remove the reading lights after this

 

[Loz]

If it's a sticking microswitch then the alarm won't "set" until all the doors are closed. Does each door show open and closed on the MFD?

 

[Spendare]

Yep, all four doors show open and closed on the MFD
Weirdly I just went to double check, after opening and closing them all, then locking up, the alarm went off almost straight away.
The internal light is flickering on and off when set to go on with the doors.

 

[Montecha]

I would check the wires under the rubber boot from the van into the tailgate. If they have run additional cabling into the tailgate then that is going to be very tight, and a pinch point.

Sounds like you have something that is a short to ground somewhere. The tailgate open / closed status in the MFD comes from the latch, that's easy to remove and see if there's any debris in the back of it.

 

[Spendare]

VW Fitted a new latch this week as thought this was the cause of the problem but appears not, although latch was sticking.

The wiring from the conversion company is a concern, electrics did not seem to be a strong area for them! I've already had a short to ground in the speaker wires, the screws they used to install the speakers protruded through the tailgate panel piecing a speaker wire onto the tailgate frame work - it caused my original stereo to burn out!

As the conversion company haven't responded to my emails/concerns with this, I got it rectified by another company that fitted a new stereo, they also double checked the speaker wires and didn't find any further issues.

the alarm problems only started after the reading lights were installed but have perhaps been hidden by the stereo burning out (this happened on the way back from collecting)

Tis driving me slightly crazy at the moment, almost wishing I'd never sold my old T5.1

 

[Spendare]

Have been trying different ways to lock the van this even after the alarm started going off within minutes of me locking it.

The internal lights are coming on, or flickering on and off every time I lock it now. Even with lights and internal sensors off, alarm was going off.

However, I have removed the fuse for the lights running off the leisure battery, disabled the internal sensors and so far, alarm hasn't gone off again!

I'm coming to the conclusion that the conversion companies reading lights are causing a power drain and possibly and ground which is triggering all this.
Time to make them take some responsibility I think... Unless anyone can suggest other possible causes?