Belled up innit?

Guru Meditation · Unread post by **Guru Meditation** » 03 Feb 2004, 15:34

Before I go to the trouble of trying to work this out from my wiring diagram in the Haynes, maybe someone already has the knowledge to help me.
I am thinking about buying an alarm as my K reg td Aura doesn't have one. Also the car didn't come with the IR key fobs for the remote locking. I've seen this alarm at Maplins: http://www.maplin.co.uk/products/module ... leno=33313
I want it to work the central locking as well as the alarm from the keyfob-question is, do I need the additional central locking interface for it to work or not? On the customer FAQ page about this particular alarm it says:
With regard to the Car Alarm (L53AF) , do you require a Central Locking Interface (CR41U) if you want to connect the alarm to the vehicles central locking or does it have one already built in ? - Paul
You may not need CR41U if your central locking is a two wire affair like YD77J.(grounded when armed output just add a c/o relay to operate two wire systems)
Has anyone any experience with this kind of thing or any ideas on how I can work it out?

rossnunn · Unread post by **rossnunn** » 04 Feb 2004, 00:10

Doesn't sound like it, it probably has a onboard output to go to the central locking.

James.UK · Unread post by **James.UK** » 04 Feb 2004, 00:41

Guru, I have a seperate fob fingy that operates the locks but quite frankly its quicker to use the key as I need it to start the car anyway, saves looking for 3 diff items in the dark. Just not worth the trouble as it dont work anyway untill you are 6 inches away lol..

Russell · Unread post by **Russell** » 04 Feb 2004, 04:22

Hi Guru,
I don't think theres quite enough published info. The alarm you want to buy has an output which can be used to trigger your central locking, but it doesn't state whether it goes low or high when the alarm is armed. Lets suppose it goes high when armed.
I expect your car central locking will have a controller with a control line that is switched either low or high to lock the doors. Lets suppose this is switched high to lock.
So you may be able to hook the alarm output straight in to the central locking control input. Or not, if either of the above are not true.
You will also need to check that the central locking input is never pulled hard to either +12V or ground, when using keys or door locks, as I think this might potentially damage the alarm system, depends on the design.
If the opposite polarity is required to operate the locks, it looks like Maplin suggest using a changeover relay.
Cheers
Russell
[:)]

wheeler · Unread post by **wheeler** » 04 Feb 2004, 04:45

it sounds just like some of the cheap sparkrite alarms you get,it has an output to controll a c/locking interface,its just a single wire that connects to the interface and you cant controll anything directly from it.it gets wired to the interface then you select the type of locking on that.
I think ZX's have negative trigger locking if i remember correctly.

Guru Meditation · Unread post by **Guru Meditation** » 04 Feb 2004, 14:50

Cheers for the advice. I think I'm going to buy the alarm and then work out if I can get it working when I can look at the detailed instructions-as you say the information on the website isn't detailed enough to work out if it can be fitted to the locking directly. Hoepfully the alarm will offer + and - triggered inputs.
Jamesuk one of the reasons I am going for this alarm is because my car came without the infra red remote control-this alarm uses radio remote control, so it should still work the locking from anything up to 10-20+m away-it should also still work when the car is iced up etc, unlike infra red locking!

Guru Meditation · Unread post by **Guru Meditation** » 07 Feb 2004, 23:04

I have the alarm. I reckon I can work out how to wire it up etc from the supplied instructions, doesn't seem too bad. But I am confused as to whether I can use it as it is to power the central locking without any additional things-on the subject the alarm instructions say:
"Orange Wire: Grounded output when armed.
The output has a current capacity of 500mA and becomes Grounded when the alarm is armed."
Question is is this suitable to work the central locking of my ZX or will I need additional bits-I'm finding it so confusing as I don't understand how the central locking works. Also if the alarm output is any good where would I connect it? I'm thinking somewhere up in the roof where the IR sensor is or maybe it would need to be connected to one of the wires on the central locking controller?
Any ideas much appreciated.

Unread post by **philhoward** » 08 Feb 2004, 01:14

Chances are that the Central Locking controller will need much less than 500mA to trigger.
Need to know how the current system works, but at a guess you'ld disconnect the plip connection to the central locking controller and if it's negative to lock, just connect it direct to your alarm. If it needs to see 12V to unlock, then you'll need either a pull up resistor or use a small relay (single pole changeover) activated by the alarm output to switch the ex-plip connection to either battery live or ground.
Anyone got any more info on the ZX Central Locking controller?

wheeler · Unread post by **wheeler** » 08 Feb 2004, 01:59

it sounds like what i suspected above,this wires controls a seperate interface,,there will be a single wire on the interface that connects to the orange wire on the alarm then likley another 6 wires on it to controll various different types of locking systems.you need at least 2 wires to control the locking.

Guru Meditation · Unread post by **Guru Meditation** » 08 Feb 2004, 05:19

Hmmm...so it sounds like I also need to purchase the central locking interface which an optional accessorie to this alarm. I wish I'd ordered it at the same time, it's another £15 but the way the alarm was described on Maplin website it made it sound like the extra interface wasn't neccessarily required to operate the remote locking and I couldn't find any detailed technical info on the alarm about how it worked etc.

Russell · Unread post by **Russell** » 08 Feb 2004, 08:03

Hi Guru,
I was deep in the bowels of my door (Citroen XM 2.1TD) messing with central locking stuff trying to stop my central locking controller from unlocking the car all the time, so I know how to wire your alarm to my car now..! [:D]
I expect your wiring system will be similar.
Two wires from each door go to switches in the locks which give a 0V signal, on one wire 0V will lock the car, on the other 0V will unlock.
On my car they are both blue. On my car, you can't get at the locks but you can get at the cable, so I stuck a pin through the insulation and measured the resistance to ground. When locked, one wire is ground the other floats, when unlocked the other wire is ground and the first floats. Check yours do the same, and especially that they float, and are not pulled hard up to +12V, in which case, the following quickly becomes bollocks, and will need a re-write.
Assuming they float (are disconnected) when not in use, you can wire your Orange alarm armed output directly to one line. This will lock the car for you when you set the alarm.
<LECTURE MODE ON>
But you need the other signal too on the other wire, when you unset the alarm. This can be supplied by using a standard changeover relay switch which you can probably purchase from Maplin for a couple of quid.
The relay has five contacts; +ve,-ve,COM,NO,NC
Connect +12V to the +ve coil contact
Connect your Orange alarm armed signal to the -ve coil contact, and the wire in one of your doors that locks when 0V.
Connect 0V to the COMMON (COM) contact
Connect normally closed (NC) contact to the wire that unlocks when 0V.
Connect normally (NO) contact disconnected.
So when you arm the alarm, your Orange wire goes low, which locks the car. It also allows current to flow through the relay, which switches the COM 0V connection from NC to NO, which goes nowhere.
When you disarm, your Orange wire floats, the relay is no longer on, and the COM 0V connection goes from NO to NC, supplying 0V to the wire which unlocks. Tarah!!
<LECTURE MODE OFF>
That's you sorted, [;)]
I wrote this explanation as simply as I can, not directly for you, Guru, (cos you seem pretty savvy), but for anyone who might like to do the same, but hasn't got a clue about electrical fings. Hope it helps. [8D]
Maybe a good idea to put a diode across the coil as well. I'll leave that last comment as something tantalising to not worry about much.
Cheers
Russell [:)][:)]

Russell · Unread post by **Russell** » 08 Feb 2004, 08:32

Hi Guru,
You can't keep a good man down at 3:20 in the AM.
Last couple of thoughts...
Where to put it?
If you know where your central locking controller is, then nearby would probably be OK.
How is the reciever aerial arranged, is it (probably) a bit of wire about 17cm long or some multiple, and where do they suggest you put that..?
Or is it a screened aerial connection, some co-ax and a little aerial?
Anyway, getting reasonable radio reception range is your priority in my view. You don't want some beautiful tidy installation that only works when you are 3cm away.
But maybe find out if you can easily attach a remote aerial, then installation decisions should be much easier.

Cheers
Russell [:)][:)]

Guru Meditation · Unread post by **Guru Meditation** » 08 Feb 2004, 18:22

Hi Russell,
Thanks for all the good info-just the sort of thing I was looking for! The detailed explanation is great and will be a big help as I really didn't have a clue how the locking worked without your explanation. I might have a bash at fitting the alarm this afternoon at which time I will investigate if the door wires behave the same in my ZX. If they don't it'll be back to the drawing board, if they do I'll try and get my hands on one of those relays-it'll save me paying £15 for their c/l interface.
As for locating the alarm....
Well the main box is roughly 10x10x10cm. The antenna for the alarm might be hard to locate as it is a wire about 40cm long that the instructions say it must be extended straight but must be angled away from the chassis and large metal objects and mustn't be grounded-so I'm not too sure how to position for best reception. Trial and error I think.
I was going to put the main box on the right hand side of the engine bay (the timing belt side) at the front in front of the PAS reservoir. It needs to be on this side really as the fuse box is on this side, underneath the steering wheel. I've also got to run a wire to the cooling fan relays to ensure the current sensing mode of the alarm works correctly if the electric fans kick in after the alarm is set. I have two pin switches for the boot and bonnet, although I should only need to install the bonnet switch as the boot has a courtesy light and so should be protected by the current sensing mode.
If I did need to wire something near to central locking controller on my ZX I believe the controller is under the handbrake cover between the driver and passenger seat.
Ah well, I've been meaning to learn some auto electrics for a while now. I'll try and post up some pictures of the kit and the installation if I get it done.

Russell · Unread post by **Russell** » 08 Feb 2004, 22:43

Hi Guru,
I presume the alarm lump includes some thumping great siren, so I guess it has to go in the bonnet area, to avoid accidentally deafening you!
A good site for the aerial may be fairly close to the bottom edge of the windscreen I would have thought, so if the unit will fit in the scuttle perhaps
The last problem is getting a bunch of wires through the firewall.
However, usually you can test the units reception with just power and ground and possibly an indicator or hazard feed, so I suggest you see how good that is before making the installation permanent.
cheers
Russell [:)][:)]

wheeler · Unread post by **wheeler** » 08 Feb 2004, 23:26

just a note about using that orange wire for the locking.from what u say this wire gets grounded when the sytem is armed.these systems need a negative pulse for about half a second then off again,if the lock or unlock wire is constantly grounded then it will continuously be trying to operate the locks.when you do it properly you need 2 wires - 1 that pulses negative for half a second when locking & 1 that pulses negative for half a second when unlocking.