Sigma Alarm/Immobiliser

[christof]

Hey gang!

I have a sigma alarm/immobiliser fitted to my mx-5.
there is a fitting certificate and it doesn't seem oem, with some splicing of wire conduit etc
There is a little black keypad near left knee, but no code in any of the paperwork!

Should i get this removed before kit project?
Will it necessitate replacement of the ecu?
I believe it is microwave rather then air pressure. Should i keep it and simply put sensors undercover/tape up?
is there a remote sensor under dash?

anything else?!

[Deleted]

Had an immobiliser on the first build and decided that the wiring was complex enough without it. Pretty simple to remove if it's still in the car before you start stripping it.
If its aftermarket it'll just be spliced into the existing wiring.
Carefully unwrap all the wiring bundles and find which wires were cut to be spliced thought the immobiliser, and simply reconnect them without the immobiliser.
It's a lot simpler than it looks/sounds.
You need some form of anti theft on the kit, this is either steering lock OR immobiliser, or both for overkill purposes! :-)

[red5]

Im with alex
Ive dealt with 3 x from differant looms ( MK2 x2 + Mk2.5) and they are pretty easy to remove - essentially as mentioned they interupt the power to the starter or similar.
All were easily spotted inside the steering wheel housing end of the ignition loom and were connected to the immobiliser from there , these were simply removed from the original cables , rejoining or bridging were required.
None of my immobilisers or sensors were directly wired to the ECU.

[squelch]

as alex said i might be better to remove it, by the sounds of it its a full alarm not just an immobiliser which means it'll probably passive arm all the time and drive you mad.
Most alarms use the door switch signal to stop it from re-arming after 30secs (they usually re-arm approx 30secs after disarming unless a door is opened or ignition turned on) and as the exocet has no doors it'll try re-arming
The key pad code would be with the original paperwork and usually gets lost you could get the code from sigma but it can be a pain,its only used from emergency disarming and programming of the alarm.
Removing it will be easier than you think either still in the car out as a loom on the floor as alex said it'll just be a matter of following the wiring from the alarm unit and rejoining the immobilisation points where cut on the original harness (probably at the ignition barrel and drivers side sill harness (starter and fuel pump)
you wont need to replace the vehicle ECU as it'll be completely separate, the microwave sensor will be small black box with an adjustment screw and it'll have a single 3 or 4 core cable running to the alarm unit

I will now say something which i may regret lol, I'm an ex VSIB and MESF approved alarm and immobiliser installer with training from Sigma, Scorpion, Toad, Clifford, Meta, Autowatch

[christof]

thanks for advice
its got central locking so imagine that the actuators are linked to alarm/immob somehow?
what is the best way of rejoining wires - suppose this is an old argument of connectors vs soldering?

[gwnwar]

Best soldering and shrink tube... next clamp/crush butt connectors

[squelch]

No argument soldering and heatshrink every time, its required on thatcham installs unless its not possible to do it (ie: chassis earth points) if your making a new loom my personal choice would be Superseal connectors (if theres a chance of water ingress) or Mate'N'lok if its going to be in a dry area for multiway connectors or if you can afford them proper aerospace connectors (very expensive)

The central locking will have a minimum of 2 wires connected to the alarm depending on if its factory or retro fitted

[red5]

I re soldered all my crush connectors recently , the connectors were failing at a ridiculous rate and i was just chasing my tail.

I recylcyled some of the Mazda push fit connectors where i needed to be able to break the loom.

[tomaff]

There is a sigma immobiliser on my MX-5 also. I was planning on keeping this,potentially, on the kit car as a bit of added security. Unless you can get some decent money for them? Has anyone sold one of these before. Can find much that match on ebay.

T

[Deleted]

May 3, 2012 20:07:32 GMT squelch said:

as alex said i might be better to remove it, by the sounds of it its a full alarm not just an immobiliser which means it'll probably passive arm all the time and drive you mad.
Most alarms use the door switch signal to stop it from re-arming after 30secs (they usually re-arm approx 30secs after disarming unless a door is opened or ignition turned on) and as the exocet has no doors it'll try re-arming
The key pad code would be with the original paperwork and usually gets lost you could get the code from sigma but it can be a pain,its only used from emergency disarming and programming of the alarm.
Removing it will be easier than you think either still in the car out as a loom on the floor as alex said it'll just be a matter of following the wiring from the alarm unit and rejoining the immobilisation points where cut on the original harness (probably at the ignition barrel and drivers side sill harness (starter and fuel pump)
you wont need to replace the vehicle ECU as it'll be completely separate, the microwave sensor will be small black box with an adjustment screw and it'll have a single 3 or 4 core cable running to the alarm unit

I will now say something which i may regret lol, I'm an ex VSIB and MESF approved alarm and immobiliser installer with training from Sigma, Scorpion, Toad, Clifford, Meta, Autowatch

This is another example proving to myself that its always worth searching the forum for old posts as I am now looking at (unfortunately) removing my scorpion alarm/immobiliser

[Deleted]

Done it now.Amazed how easy it was, 10 minute job!