dual zone proximity sensor

My car is fitted with a DEI 508d proximity sensor as far as I am aware, and appears to be mounted under the centre console area on the floor of the car, thats if its the clear box with two lights on that I think it is?

Anyway, the sensor from most areas works fine, the warn away works when you are stood upto the car as soon as you look into the window at either side, and the full trigger is activated just as you put your arm through either window.
The problem is, the car is only a small hatchback, yet when the boot is open and if my arm is placed in the warn away triggers will sound, but to trigger the full alarm my arms need to be in the back seating area.

Is there a way to increase this without making it too sensitive elsewhere?

As far as I know, not without adding an additional sensor. The sensors use a circular field to trigger so increasing the radius affects everything. That is why a lot of people will use 2 sensors; one up by the front of the car, and one near the rear to help achieve more of an "oval" protection zone.

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Kenny
Owner / Technician
KKD Garage LLC
Albany, NY 12205

Make sure the mounting tabs are facing the front and rear of the vehicle. The ideal location for the sensor is in the center of the vehicle as possible. Also there are two dials on the sensor that can be adjusted to increase/ decrease the warn and full trigger zones. The warn away has a green LED and full trigger has a red LED. I can't find a manual for the 508D but it explains how to adjust the zones. If this isn't sufficient you may have to add a additional sensor but I cant see that with a hatchback.

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I drink current, eat ohms, and bleed voltage

I gave up years ago on small hatchbacks in the UK, I just concentrated on the driver's area making sure there's a trigger and connected to the alarm, even though I roof mount them where possible.
Funnily enough the only car I've ever had real success with was an X5 using Clifford's digital dual prox sensor that's only compatible with G4 and G5.
Even my own with a 508d in the roof lining, centre roof, I can't reach the hatch.


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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

offroadzj, I understand...I was hoping there would be a simple fix but unfortunately not, would it be worthwhile adding a second 508d inside the rear hatch area? If that would even be possible to install a second sensor I am unsure, or even some ultrasonic sensors in the rear, although I hear these are temperamental.

Pts760, are these the tabs which look like screw holes? These are indeed facing this way but the sensor is stuck down rather than screwed it seems, the adjustment screws are at the front offside edge of the vehicle. I have been given the adjustment instructions with the alarm but I dont feel I should adjust it for risk of messing it up, as if it is already perfect at the sides of the car surely these will be expanded with adjustment? The sensor has been placed under the centre console area as I say between the handbrake and gear shifter in a rather large gap between, I'd say it's as near the centre of the vehicle front and back wise as possible, any further back would be too near the handbrake I assume.

Howie II, you may indeed be on the money there, it' seems to be a good trigger and warn away sensitivity for both driver and passenger area, even when sat in the back seat if activated and after a few seconds if I move about there will be a couple of warm away beeps before the siren triggers pretty much straight away, it's just the rear hatch area which doesn't trigger fully, only the warn away beeps are heard.

At worst case this isn't a major problem as I only usually keep a wheel brace and tyre inflator in the boot, if a thief was to climb over to attempt to steal the car the alarm would trigger then anyway, but it's nice to have complete piece of mind.

Thanks

I've never seen one that was actually screwed into place, my recommendation any way would be the roof lining, ground plane from the roof, no signal blocks from the chairs etc.
What vehicle and is there a sun roof?
Any yes I've often extended the cables to accommodate roof lining fitting, no adverse effects, heck you've got to run the antenna up that way anyway.
Smart car aside you will NEVER cover a whole vehicle.
The only problem with u/sonics is that they can be unstable if you drive t5he vehicle on a winter's night, then park it. The sudden temp. drop can trip them. Also of course you can't leave the windows open, but on a small hatch, Fiesta, 206 they DO cover the rear.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

The roof lining does seem like an idea, if mounting upside down is possible? The only issue I would have is the roof lining is completely different to most vehicles in that it is a thin stretched vinyl type material not a thick furry carpet like item, I have a feeling the sensor would leave a bulge in the lining.

Do you feel moving it to your roof would cover the boot area or would I still have problems if you say that full coverage will never be achieved?

I shall leave the ultrasonic sensor idea as Iam not a person to cope with false tripping all the time.

Thanks again

Again what vehicle. And yes as long as the emitting surface (top, screw flanges are on the bottom) faces the car it WILL work better.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Sorry, it's a Toyota vitz, if you know what that model is?

I've just attempted to open the boot again and the alarm full triggered immediately which is quite baffling

Please don't try to be clever, I've done 'em all!
Basically a Yaris, early version didn't have a trunk (hatch) light and we had to add one, later post 2005 (02 in China)had a trunk light, if you have one and it's connected to the alarm, that's your answer.
Since this is a grey import I'm assuming a Cat I alarm was required by your insurers, from the 508d, I'm assuming it's either a POS 460/480 or a rubbish Toad.
I probably know more about it than you.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

There is no need to be arrogant, not many people know of the vehicle even motor factors, I wasn't trying to be clever by any means, no it does not have a trunk light, would I be best adding this and connecting a sensor to this ruling out the need for another 508d? It is a viper alarm with page fob but I am unsure of the model no until I check the docs? What's so bad about this alarm?

I'm not being arrogant just all knowing, how do you think I knew it needed a Cat I alarm? And I guessed which one didn't I.
Insert a trunk/hatch switch, far cheaper and IMO more reliable and effective*.
The alarm you have is a 480XV and it's worst feature is that POS remote, usual lifespan about 6 months before the frequency crystal or battery mountings fail.
And yes I do know more about your car and alarm than you do.
*Ref the trunk switch, did the installers leave in the original ultrasonics? If that's the case your rear hatch should be covered, if not look at the owner's manual it shows you how to increase the sensitivity.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

I do apologise must of just been wires crossed, that's true I believe all greys need a cat 1 usually?

If I recall correctly they did not leave in the u/s sensors if it ever had any as there is nothing at the a pillar area, the blue wire has been run to the boot area I did notice this when installing a more oem fog location, is it just a case of drilling into the boot area for the switch and securing screw?

In regards to the remote I also have a spare 4 button remote but has no paging feature.

All Euro market cars required a Cat II (immobiliser) at least before the individual vehicle got type approval or even insured for the UK, thus this also applied to Grey Imports.
It's actually a PITA to mount a switch in the hatch area. I can't remember the last one but look very carefully, I think I used a long reach switch on the striker panel to one side.
The blue wire is correct, but test, get it loose sit near the wire, close everything and turn off the proxy (via remote see owner's manual).
Wait 5 seconds then ground (earth) the wire to a convenient piece of bare metal. If it triggers the alarm that's it.
Most people end up using the plain remote, it's response time is faster.
BTW The original installers should have installed a hatch switch along with a bonnet (hood) switch, MANDATORY for Cat I.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Ref the switch:-Seems I blew it, armourauto.com, page 535, PC5-53.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

I see, that must be the reason many insurance companies insist on it. Pardon my lack of knowledge, but what is the striker panel? I will check that product out I assume it's a page of the catalogue, as I recognise the part number.
Would it be simpler or even possible to connect a contact switch?

I did wonder why they hadnt connected it, I assume they route the wire that far and realise there wasnt an existing switch so gave up, as the bonnet has been connected

The striker panel is where the lock is.
What do you mean by contact switch? Technically ANY switch is a contactor!

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

I'm sure my lock is on the tailgate itself, it's on a hook type handle.

Sorry, I didn't make myself clear, as in a switch with two pads that have to be touching each other?

Thanks

As in a magnetic reed switch? Up to you.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

That one, I was struggling to think of the correct name, is there one available suitable for alarms that works well?

Thanks

Look around the page I quoted, they all work well if correctly installed.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

508D is one of my favorite topics. Listen to Howie on concentrating on having protection in the driving area. If you are worried about the back hatch, put in a truck pin that will activate if someone pops open the back. The dual zones of the proximity sensor will be blocked by any metal they have to penetrate. Also keep in mind the zones take a few seconds to set before they will be active. this may be why you get a full trigger one time and not another. Temperature also makes zones more sensitive when cold out, and less sensitive when hot. It was noted by someone who has a DEI certification that the zones don't fully set for 20 minutes after arming alarm. Not mentioned in the manual. Not sure of the accuracy of this but might be accurate in your case

Birdman41; Clifford used to be trunk, hood instant, doors 15 seconds and prox/mux 25 seconds.
Also after 3 inner zone triggers the 508d will TURN OFF, has to be reset by turning ignition on and off.
508d itself won't actuate for 4 seconds.
Your comments on position echo why I always try to go for the roof lining where possible.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.