On mine it's worked perfectly ever since I've owned it

Until chap who regassed the aircon noticed that the wire connecting it to the push-button mounted on the slam panel was sheared....he'd taken out the pipework to replace a leaky part to reveal the break (I was watching and he didn't do it!)

So I've joined the two ends together (single core), cleaned up the whole push-switch unit, and now there's a problem

With plibber, lock car = 1 plib, 1 flash, locks clunk

"Before repair", unlock car = 2 plibs, 2 flashes, unlocks

"After repair", up to 10 mins after locking, the alarm goes off!


To turn this off I point plibber = 4 plibs, 4 flashes, locks clunk
-another plib = 1 plib, 1 flash, silence
-another plib = 1 plib, 1 flash, silence
-another plib = 2 plibs, 2 flashes, unlocks




This sort of sequence (with 4 plibs) does happen intermittently if perhaps one of the doors has not been properly closed - a "run-round" of the above sequence seems to sort it.


I have tried disconnecting the wire completely from the push button, which to my mind should replicate the conditions before "repair", but without success.

I've checked the bonnet push switch which is engaging properly.

It seems the principle is to dis-engage the connection by depressing the push-switch when the knurled black knob on the bonnet underside hits it.

Any suggestions gratefully received!

Try disconnecting battery for a minute to reset everything first, maybe that'll fix it.

If you know where the alarm box is I'd try disconnecting the other sensors just to confirm the problem is only with the bonnet switch.

If still the same then I'd cut the wire to the bonnet switch well back from the repair/disturbed area and insulate the end nearest the alarm box to see if that helps.

If still no luck then remove the insulation and connect that bare end of the wire to an earth point nearby.

If still not working then probably a problem with the alarm itself.

Cheers Graham, will start working down the list!

So the only detail I hadn't reported was that the interior alarm warning light was blinking very feebly during the current issue.

After disconnecting the battery and reconnecting it has apparently sorted itself and the warning light is now flashing brightly.

Cheers Graham, right again!

First rule of fixing anything electronic.... "Have you tried switching it off and back on again?"

First rule of fight club.........

Ah, the insomniacs....yet to see this!

I've since discovered that 4 flashes after unlocking signifies that there has been an "activation", and the next step is to switch on the ignition and count the number of flashes from the warning light. Toad alarms are now manufactured by Scorpion, whose tech dept kindly mailed me a user manual (but no schematics).

The faint warning light has returned though - is this likely to be a disconnected or loose earth?

Here are some pics of the passenger footwell (with a white background for easier viewing) where the alarm loom comes in from the rhs through the bulkhead -


The vertical black wire leads to the windscreen sensor. Another black cable is a dead end, folded back on itself. A pair of yellow/black wires and a blue wire disappear into the wing but before that a second blue wire has been cut and lies idle.

There are two earthing points (yellow and red crimps) which I've inspected.

Could the truncated blue be a disconnected earth?

If this section is all fine should I work through the driver's side then the rears to check earths too?

I should say at this point that sometimes the warning light returns to shining brightly.

you haven't found the main box then? ecu etc? find the main box it should be securely fitted to chassis with Thatcham screws,unless its a c4-c5 type where all the wires come out of the siren etc, find out which model alarm you have and I should be able to help as I fitted these for a living some time ago.

It's a C4. The unit sits on top of the n/s wheelarch and the loom snakes down and through the bulkhead where it splits. There's also a single strand from the unit leading to the bonnet microswitch mounted at the side of the radiator.

Annoyingly it hasn't played up for a week or so - I'm waiting until it does so I can read the code from the no. of flashes from the warning light.

ok, doddle I must have installed over 1000 of these great alarm to be honest blue wire is optional sensor duel zone wire etc wire I say prob as people fitting alarms use any wire they have available to lengthen o.e.wires,how many ultrasonics do you have fitted? as in your pics you have a spare connector? maybe have a microwave installed, anyway I can advise you on programming fault finding installation etc, do you have a test light ,multi meter, power probe etc, and how competent at soldering, looming, etc?

Thanks very much

So at least I know not to worry about the blue wire.

Yes the flat black connector maybe should go somewhere but is clearly flapping about uselessly atm.

There are I think only 2 ultrasonics which run up inside the door seal.

Tbh this sort of wiring and electronics is not my thing although with a good howto I've changed an inverter cable on my macbook!

I know a chap though who can't get enough of all this stuff and would likely rise to the challenge - he eats schematics for breakfast

Update...

The alarm went off spontaneously at midnight!

This time I nipped out, disarmed it, turned on the ignition and counted the flashes from the warning light - 6.

This number corresponds to (one of) the ultrasonics triggering the alarm, so I assume there's a fault in their wiring...

At least it gives me a lead to check tomorrow!

If it's particularly windy, air blowing through the vents can cause the interior ultrasonic sensor to trigger the alarm, so closing the vents or putting it on recirculation should prevent it.

Interesting - I tend to have the circulation set to demist vents but have recently had it set to dashboard....

Here's the culprit

It's been "potted" originally with a white compound, but removal of this has exposed a fixable item

I'm assuming a break in the earth would have been enough to activate the alarm....

Bl**dy thing went off again tonight

What's more it didn't even give me a 'code' from the warning light when I switched on the ignition

Can you put the siren on silent? Not a solution of course, but helps to keep the neighbours happy