300 series immobiliser ( Ranix cars )

Post by **shimon340** » 28 May 2006 07:00 pm

Hi guys!

This also applies to the 400, 360 and 200, 700 and 900 which use the Renix ignition... (did the 900 ever use this?)

I was taught how to do this when I was just starting to learn 340 mechanics years ago but have never got round to it....

(Following the unfortunate break in to my dads 440 yesterday - they got access to the ignition barrel but were disturbed it seems and left it as is )
Ive been promoted to resurrect this idea and wanted to see your guys opinions..)

I used to immobilise my car by removing the lead from the Renix to the distributor but a better idea is to fit a switch to break the positive feed to the Renix. And this is what I plan to do in addition to fitting a Disklock Thatcham category 3 steering wheel lock.

What is the wiring rating for the power feed to the Renix? If I use too thick wire and the switch is mounted to far away from the Renix ( ie in boot ) is there a potential problem with the supply voltage being too low due to the too high resistance of the wire?

What rating should the switch have?

Im also thinking about cutting the supply to the starter motor - using the thin blue wire - not the large one from the battery !

This way the ignition and the starter could be cut so if any of those little ******* try again, hopefully my car will appear to be broken down!!

look forward to your input!

Shimon

Post by **shimon340** » 28 May 2006 07:01 pm

how embarrasing!! I was rushing!!! It RENIX not Ranix

Post by MJ » 28 May 2006 07:38 pm

I have no idea for the practicallity, but how about a switch to cut off the power to the fuel pump (if electical). Therefore the engine would just turn over and not fire?

I like the starter motor idea, but there's a lot of power going to it, you'd not really want all that through a small wire, but perhaps a relay on a lower power circuit to a kill switch...

Post by **pettaw** » 28 May 2006 08:01 pm

The switched live to the Renix goes through the igntion relay, but I don't know what the current draw is I'm afraid, but I wouldn't think it would be too big. On the alarm systems that are fitted to these cars, they make a break in the wire from the igntion barrel to the igntion relay.

The starter solenoid also I've no idea how much current it draws but it won't be too much either.

Post by **jtbo** » 28 May 2006 08:23 pm

Megasquirt is good here too

I have switch that kills Ms power, megasquirt controls ignition and fuelpump + injection so all of those are shut down too, I made this primarily for safety feature but also good for antitheft.

you could place switch for renix under dashboard or glove box, easier to access but still those who don't know it won't be able to start car.

Post by **Chris_C** » 29 May 2006 12:59 am

I wouldn't bother with the starter solanoid, that wire can cause stupid amounts of problems to us when we want it to start!!!

I've always gone with the fact our cars have the best immobiliser on them anyway (apart from GLT's) there can't be that many of our up and coming round of t*ssers that have been taught what the choke is for...

If you are going to do it, as Andy says, stock systems use the ignition barrel wires, and just cut ignition, but I'd go for the renix feed too. I don't have the figures to hand, but stick an ammeter in series when (if) you cut it, and relay it (Any current rating bigger, I'd guess a fog or spot relay would be fine). I'd put the relay under the bonnet, by the renix, and earth close, and just run the single coil feed to whatever you want to immobilise the car with (remote locking... standard switch etc)

Just remember, and this is the reason I only ever did an alarm on Kar not immobiliser, if something goes wrong, wire comes loose, anything, you will loose engine. Loss of engine means going onto econo brakes, which if you are doing Standard Motorway Cruise Speed, could be intresting, no power or stopping...

Post by **shimon340** » 29 May 2006 12:19 pm

Thanks for your help guys.

Ive noticed that one the lower steering surround is removed it is very very easy to get to the ignition barrel wiring - amazing how vulnerable cars were before radio immobilisers came in....

Im thinking of fitting a extra switch ahead of the feed to the ignition relay in the fuse box. This means the ignition barrel looks unchaged. If I make a cut here by igntion barrel, it would be seen / obvious and it could be bypassed by thieves..maybe...

I'll put an ammeter to the feed to the igntion relay then, as you say Chris I'll get a higher rating relay for here. Im trying to remember my GCSE electronics here, Ive been a chemistry student since 99 and doing chem research since.... so the switch will cut the feed or ground to the ignition relay. I'll then do the same for the Renix live feed, measure ampage and then fit relay and switch. It'll be a 'try it and see' system but Im planning something similar for the 440 also....

thanks for you help everyone!

enjoy your volvos

Shimon

Well, I guess is teaching me more about car electrics but thieves are annoying and should be shot!!

Post by **Chris_C** » 29 May 2006 12:30 pm

Yeah, I'm in agreeance those are the two best places to cut! Lets us know how it goes mate, I am very intrested in this, as I said, it's somthing I looked into when building my radiocentral locking/alarm thing, but that was 5ish years ago, so I a) didn't have the electronic knowledge and b) didn't have the car knowledge to pull it off. As poeple who have seen Kar's remote in a bad mood will say... it can be tempermental, although at least I now know why it is and how to stop it.

Post by **jtbo** » 29 May 2006 01:19 pm

Pick one of these:
http://www.killsometime.com/animations/ ... asp?ID=115

Ex Navy seals is my favorite

Here is few more:
http://www.stickdeath.com/autothft2.html
http://www.stickdeath.com/autothft.html
http://www.stickdeath.com/2005auto.html
http://www.stickdeath.com/2003auto.html

Post by **shimon340** » 29 May 2006 02:44 pm

cool... I'll keep you all posted

Post by **classicswede** » 29 May 2006 07:26 pm

Vicky's car has a good one - switch it to petrol and if they suss that one out it wont start unless you gently press the throttle

Post by **foggyjames** » 31 May 2006 10:05 pm

Thicker wire means lower resistance, all else being equal.

Cutting the positive feed isn't a bad idea at all.

cheers

James

Post by **petefarrell360** » 11 Jun 2006 06:50 pm

My old GLT had an immobiliser which was very useful indeed. Infact it had two, one as part of the remote central locking alarm system, and then a switch under the dash, which allowed you to just turn it over on the starter, no dash lights and nothing else so it would never catch and start. I never got round to looking at how it was all installed, or swapping it over, might be a project one day. So with both immobilisers enabled, there really wasn't much chance of anyone starting it there and then.

And then there is the Derby immobiliser, that is something else! In the diesel 360 I bought it had a very unique form of immobiliser, in that in the centre console cubby hole there were two switches at the back that needed to be switched correctly, another hidden on a bracket under the gear stick leather cover, and then the best part of all was the fact that the ash tray had to be open to start it, as it was wired into the glowplugs and had a switch on the back of the tray!

Good idea though Shimon, it's so annoying that we have to go to such lengths to keep the thieving *******'s from stealing our property.

Pete