Alarm issue - constant door open

[Bling]

Dynatron alarm.

Started with the boot sensor not working 100% unless pushed down manually. (Just last night). Now this morning the door sensor is showing as open but there is nothing it can be as both doors shut, boot/bonnet isolated... hard to set an alarm when you can't "shut" the doors

Thoughts from the auto sparkies / people that have had this problem?

[BZG Wagon]

Are you sure it's not still an issue with the boot; i.e. does your boot trigger your door sensor (mine does - ditto with my old corolla)?

I'd check that boot switch again and look for corrosion or a short.

[Bling]

Well I pulled the plug on the switch so that it thinks its shut, well I assume that's what it thinks as last night the light on the dash went out when I pulled the plug. Then this morning it was back on again FUUUUUUUUUUUU

[wde_bdy]

Door switches generally earth when the door is open, so if the wire back to the alarm is damaged it could be earthing out. Trace the connection back to the alarm and check. Does the interior light come on at the same time? if not then the problem is more likely to be the alarm itself.

Callum

[BZG Wagon]

Like wde_bdy said they earth when open. See if it shows closed with both door sensors unscrewed.

Likewise are you sure your now unplugged boot connection is not earthing somewhere?

I'm a big believer that more than one random fault is unlikely to happen at the same time as another (not to say that it doesn't happen). If your boot sensor caused an issue last night, then I'd be surprised if your doors or bonnet are also causing the same issue today.

[Bling]

Will take off the door sensors next. The switch for the boot was a plastic plug, so pretty sure that's not earthing. Really hoping it's something dumb tbh. Will check interior light too. Boot light was working normally when boot switch was connected. It may or may not be related to the boot switch. I spent half an hour in the dark pulling it off and checking it out and reinstalling it to have the same issue. Switch looked fine.

Has just happened for no obvious reason out of the blue. Unplugging boot fixed the issue last night, so I thought it was that. But then when it was happening again today it had me stumped. So after snapping off the wire on the bonnet sensor (no tools + frustration) and having the boot disconnected i'll have to look at the doors.

Cheers for the ideas

[KwS]

bit random and likely unrelated, but when my laurel blew its interior light fuse it would trigger all the door open lights, and make the alarm a PITA. New fuse, no issue.

[328FTW]

Mine has started doing this, the door switch contacts have gone all weird I think. Gunna fix it tomorrow and see what I find.

[Bling]

Seemingly flat battery now from being left for ONE night with dash light on.... hmmmm. Will charge it tomorrow while at work. But surely a battery on its way out wouldn't cause this sort of problem?

[sergei]

Seemingly flat battery now from being left for ONE night with dash light on.... hmmmm. Will charge it tomorrow while at work. But surely a battery on its way out wouldn't cause this sort of problem?

Door light drained the battery. If you have NS40 sized battery, they don't really have a lot of capacity to start with, combined with aged they can be at fraction from new. Say if a light consumes 1A (a 12W boot light), 8 Hours later you have 8Ah, which is ~ 25% of brand new capacity consumed. If the battery is at 50% capacity to start with, you can see that it will drop bellow starting voltage and bellow ability to produce enough current to turn engine.

[Bling]

Only light left on was the dash light bulb Still no closer to finding the problem yet. But may have to start pulling interior panels to trace wires

It's now just random. I have have it working normally, but if I shut the boot too hard, it will flick the dash light back on. Unplugging the boot switch doesn't switch it off. So i'm thinking a wire is earthing somewhere other than it should be. After fiddling around I managed to get it to switch off, and slowly closed the boot, and it stayed off.

Gremlins ftl

EDIT: Looks like the boot light comes on even if boot switch is unplugged. At least that's what I remember from 2:30am this morning being woken up by the alarm going off FUUUUUUUUUUU Certainly seems intermittent now. Perhaps a cat jumped on it and bumped a wire.

[MAGN1T]

Your alarm is probably toast.

It'll have small electrolytic capacitors on the circuit board, leaking.

Steve