I have a Clifford 50X .. now obsolete fitted last spring .. and it would flatten your battery in 10 days .. it is currently somewhere in London while some Clifford guru looks into it's guts to see why the turbo timer stays on all day long... I fitted a 50% larger battery to stop this .. and now have a battery conditioner that the car plugs into while in the garage (second car/toy so not daily use).

So .. beware the fact that an alarmed car may drain your battery faster than you think .. and these cars have small batteries on purpose (lightweight) .. but this makes them susceptible to alarms..

So ... get a guarantee about how long the car can last .. written .. when you get one .. I would want to see less than 30 mA total dark current with the alarm .. the car and radio etc will take 8mA ... so that leaves 22mA for the alarm .. and the Thatham limit is 30mA for the alarm but I would expect the new generation alarms to get down to the 22mA I am talking about.

.. and get a Thatham approved one .. it makes a selling point and guarantees the performance. (3/00)

I have a Cobra alarm-immobiliser which is Thatcham Category 1 approved. (I can't remember the exact model number but it's probably been superseded now anyway.) I've not had any problems with it. The fact that it is Thatcham approved should mean it is up to pretty high standards. It's worth getting a Thatcham approved one because these are usually the only ones that will entitle you to a discount on your insurance.

Just in case you don't know, Thatcham Category 2 is immobiliser only. Category 1 is alarm+immobiliser. So to discourage prying arms you need the latter.

There are two main types of movement sensors to trigger the alarm - air movement and microwave. You need the latter so that you can leave the car with the top down and the alarm on. Then if some foreign body enters the area (e.g. a thieving arm) the microwave field is disturbed and the alarm goes off. This is exactly the system I have on my car, and it works well, as demonstrated when I leave the car parked with the top down at home in the summer - all is fine until nextdoor's cat decides it wants to go to sleep in the footwell and the alarm goes off when it climbs in!

I don't think it matters a great deal which brand you choose as long as it is reasonably well known and the dealer/fitter is satisfied with the quality and performance. All the brands that have been mentioned so far (Meta, Clifford, Cobra) are well known brands. Quiz the installer about their recommended brand - after all they will know which ones cause the most problems/callouts/returns. I would definitely recommend using a local specialist car alarm installer to have the work done. You want them local in case you have any problems, so that you can go and bang on their front desk if necessary - not an option if they are a mobile installer.

Personally I would go for a small independent. You should find the prices are just as competitive as chain stores. Check the Yellow Pages and ring around for prices and what system they propose to fit. Also look under Car Hi-Fi dealers - a lot of these do alarms also and are competent with removing panels and doing wiring, etc.

Also check out how much extra they would want for central locking (if you're interested). They can wire it up to the alarm at the same time they fit the alarm. They may try to charge you an extra £100 but haggle - if you get it down to £50 that's a very reasonable figure.

For reference the motors can be had from Maplin for £9 each and a universal central locking relay (if required) costs around £20. They would obviously get them cheaper so £50 is a reasonable price. I fitted central locking myself, but it really is a pain in the a*se job and time consuming, so if you can get it done at a good price I'd recommend it.

Don't get talked into having a non-microwave (i.e. air movement) alarm fitted - it will go off even with the roof up if it's windy enough for the roof to be buffeted a bit! (3/00)

I have got the microwave alarm too and can confirm that "foreign" bodies will set it off - in Spain last year my car was in the garage of the villa we rented - top down - and in the middle of the night the alarm wakened us up. I couldn't see any reason for the alarm going off, so finally switched it off.

Next morning I found a snail on the floor on the passenger's side - it must have dropped from the ceiling into the car thereby disturbing the alarm! (3/00)

My alarm (don't know what it is - fitted ten years ago) besides having central locking also closes the windows. This makes it more difficult for people to root around when the hood's down. It then has to have an override for this function in case the full length tonneau is fitted (this overlaps the windows) - this is located in the armrest box (whatever that's really called). My MX-5 does not have a remote boot release so the boot is reasonably secure in any case (and also has an alarm switch fitted).

I'd reiterate the comments re the current drain of an alarm on a second car. My battery went flat several times until I thought of switching the alarm off - it's been fine since. Luckily the car lives in a windowless garage which I think is more secure than a normal one since it's also fitted with an electric opener thus reinforcing the door. (3/00)

Bad relay in the alarm. It probably got a bit sticky because of the hot weather. No need to replace the alarm (your friendly mazda dealer will try to sell you a new alarm).

Relay costs about £2...labour 1h, but I doubt your friendly mazda dealer can (will) do this....you'd better take the alarm to a alarm fitter and ask him to replace the relay. (5/00)

My GT auto Alarm, fitted by a fitting company cos its a requirement byu the insurance company for CAT1 alarms, has a microwave sensor which is located around the ash tray area.

It is underneath the central console, so you can still use the ashtray (but not for smoking in my car!). This clearly means prying up bits of the dash and console - but thats required to get the wiring back to the alarm anyway. (5/00)

All this talk of alarms and how few problems people have had has prompted me to tell my story:

In May last year Mazda fitted an alarm (and central locking upgrade) to our '5 for £370 (inc. members club discount), which turned out to be a Cobra 7982(?).

All worked fine to start with, until half way though our holiday in Italy in June, when the alarm went off in a thunderstorm. After that, it went off unexpectedly, and unpredictably, either hood up, or hood down. On returning to the UK I had Mazda look at the alarm again and they claimed they had adjusted the microwave detector. The alarm showed no improvement, and so I complained to the After Sales director, who arranged for the microwave unit to be replaced.

All was well for a while until the alarm started to go off again for no reason. Back to Mazda: "We've adjusted the microwave detector again - should be OK" Since then, the we've barely used the alarm since it tends to trigger for no apparent reason.

Is this:
a) a duff alarm
b) a dodgy microwave detector
c) a poor installation
d) dreadful customer service from Mazda?

What do you think I should do next? (1/01)

Sounds like it's just a bad actuator, but the relay box that drives the solenoids on this alarm is pretty nasty. Mine died in such a way that it left the solenoid powered and burnt it out. :-( But as both solenoids are driven by the same power (I think the blue/purple wires off the control box) I can't see how this is your problem. This box is usually behind the glove box, and besides the two solenoid wires and the green alarm state wire it also has red/black power feeds. Easy box to spot.

Then when you squeeze in through the passenger door, the engine won't start as, I guess, the immobiliser bit still thinks the alarm is armed, but it doesn't actually sound the alarm. (maybe ?).

This bit I don't understand at all. The alarm box has a green wire that goes to the door solenoid control box. If this box sees the alarm disarmed it tried to unlock both doors. Your passenger door unlocks so it looks like either a bad solenoid control box or a bad door motor.

The car also has a separte Sigma immobiliser.

Maybe this needs to see the driver's door opened? (guessing!)

Is this likely to be a fault with the door locking mechanism that I can fix easily, or is it more likely to be something wrong with the alarm ? Any bright ideas anyone ?

My first guess would be locking mechanism. When it happens next time why not unlock the driver's door with the key and check the car starts? If all is OK try just adjusting the door lock mechanism and the solenoid. (1/01)