DIY alarm / immobiliser installation

[bongojoe]

There are a lot of fairly cheap alarm / immobiliser kits on eBay. Are these easy enough to fit?

I've already done a lot to my Bongo (reverse parking sensors, coolant alarm, new voltage-sensing split charger, rewired most of the conversion electrics, etc.) without incident so very comfortable getting into its electrical innards.

I am however slightly worried about getting into ignition and fuel pump electrics.

Any advice welcome, and of course any recommendations on a good kit to buy.

Thanks!

[g8dhe]

See the factsheets: http://www.igmaynard.co.uk/bongo/member ... switch.pdf

[bongojoe]

Didn't think to look in there - thanks!

[helen&tony]

Hi Bongojoe...
You have P.M.
Cheers
Helen

[the.sasquatch]

I am about to fit my alarm in the next couple of weeks. Done a couple on previous vehicles and the advice I have is to give yourself plenty of time, prepare well by studing wiring diagrams etc and make it as neat and as hidden as possible. The more factory you can make the install look the better. I'm just getting copies of all the wiring diagrams i need and will make sure i know where everything is before i start. If you get stuck or need any help drop me a PM

Cheers

Andy

[Dodgey]

It's not difficult, it's just a hard day's work. It's well within your skills.

The hard bit is finding and tapping into the currect wires for the door switches. They are all spelt out on this forum, but they are just fiddly to get to - up high in the drivers footwell. You get to them, then you have to tap into them. Like I said, not hard, just annoying.

The fact sheets, or other posts on here, spell out exactly which wires are for each door switch - saves you a lot of time! Oh, and make sure you have a multi meter for testing cables - I can't imagine doing this kind of work without but people still do.

The other bit - imobilisation - dead easy - sounds like you are getting PMs about it. It's the easiest part.

When I did my whole alarm (ebay jobby) I did it with remote central locking (had to add a new servo motor) , volumetric microwave (for the roof tent), door switch monitoring (so the alarm knows when you have opened a door, so it doesn't auto arm in error) - took a day to do and I was relieved when done - and I'm into electronics and cabling.

[nth]

Just remember if you have an LB with the interior lights wired to the LB when you connect the alarm (which will be wired to the starter battery) to the door switches you will be effectively connecting the batteries together in parralel.
I fitted an extra switch to all 4 doors specifically for the alarm to avoid this.

[bongojoe]

Thanks for all your help and advice, folks. I think this might be a project for the Christmas holidays!

[Dodgey]

Just remember if you have an LB with the interior lights wired to the LB when you connect the alarm (which will be wired to the starter battery) to the door switches you will be effectively connecting the batteries together in parralel.
I fitted an extra switch to all 4 doors specifically for the alarm to avoid this.

I'm not sure that's true. The wire of the alarm for sensing the door switch activation doesn't loop straight back to the alarm's power input. It terminates in a circuit inside. I've got my lights connected to my LB (via the fuse board) and I have not linked my batteries in parallel. Either with the doors open or closed. I'd know, I test the battery voltages independently , frequenty, as I'm testing solar chargers.

Perhaps you has a very specific type of alarm?

I also install a lot of solar chargers in Bongos that have after market alarms fitted and Willington kits (or my kits) fitted - so they have the LB powering the lights, and I've never seen the batteries linked in parallel other than when the split charging kit is activated, or the power management unit links them (ZIG) in towing mode.

[Simon Jones]

On my previous Bongo, the alarm was triggered by monitoring the voltage drop caused by the interior lights coming on. This caused problems as the alarm was connected to the SB while the lights were on the LB. Ended up putting the lights back to the SB and no further issues.

[Dodgey]

Ahh - that's the older style alarm that senses voltage drop on the battery and uses this to assume a door has been opened (and thus switched a light on). Most modern alarms don't do this any more. I came across one of these a couple of years ago when a customer had a dual battery solar charger off me, and it kept setting hsi alarm off as it started charging the starter battery - which triggered the alarm

[roosmith]

Not sure that is strictly true either Dodgey - I have an Autowatch alarm that monitors the contacts on each door (not the lights) however it also monitors the voltage via the siren hold-off. When I installed one of your dual battery chargers when it stopped charging it sensed the drop and went off. I had to install a volt applied siren instead. It's not necessarily a case of old alarms, just different types. I went for the Autowatch one, as it added all the features I wanted like auto lights when the key is taken out the ignition, remote lighting and central locking.

[nth]

Just remember if you have an LB with the interior lights wired to the LB when you connect the alarm (which will be wired to the starter battery) to the door switches you will be effectively connecting the batteries together in parralel.
I fitted an extra switch to all 4 doors specifically for the alarm to avoid this.

I'm not sure that's true. The wire of the alarm for sensing the door switch activation doesn't loop straight back to the alarm's power input. It terminates in a circuit inside. I've got my lights connected to my LB (via the fuse board) and I have not linked my batteries in parallel. Either with the doors open or closed. I'd know, I test the battery voltages independently , frequenty, as I'm testing solar chargers.

Perhaps you has a very specific type of alarm?

I've done loads of car alarm & immobiliser installation over the years of working in new car dealerships (used to be an approved fitter for Meta, Cobra & Texalarm systems).
I had never come across the situation before though of the dual battery system with certain items coming off the second battery & I never really gave it a second though either but I think it was actually someone on here that mentioned it previously & it kind of made sense that there must be some sort of electrical connection between the 2 batteries if the alarm is powered by the starter battery & the door trigger wire from the alarm is connected to the lighting circuit which is powered by the LB.
When the doors are closed the wire for the door pin switch will be +12v from the LB as the wire is not earthed yet. I suppose depending on the specific model of alarm this may be blocked electronically inside the control unit buy diodes or something (im no electronics expert by the way )
I though best not to take the chance & fit separate pin switches for each door & also a bit more secure as everyone knows exactly where the factory pin switches are & it kind of looks to me like the front door ones would be quite easy to defeat.
If I have some spare time at some point & have the panels back off for something else I may temporary link the switches together to put the theory to the test.

[g8dhe]

Linking the "live" side of the switches will parallel the batteries via the associated lamp. However that isn't the case when an alarm circuit senses the voltage of a battery or when it monitors the voltage at the switch, in these cases the two batteries will remain isolated in any modern or standard circuit.