Dome/courtesy light delay & dei 528T

Hi,

I have a Selca car alarm which has no dome/courtesy light delay.

I have bought a DEI 528T Pulse Timer...how do I wire this to create a delay for my dome/courtesy light?

My vehicle interior light is negatively switched from the doors and my alarm has a negative when armed output.

Many thanks,
Mo

Are you looking for dome light supervision? In other words do you want the dome light to turn on when you unlock using your alarms remote? If this is what you want to do, then wire the 528T like this:

Yellow = Ground
Brown = To dome light - trigger wire in vehicle
Black w/stripe = To unlock output - from alarm
Black = Ground
Red = +12V Fused supply

Doing this will put the dome light on for the timers duration every time you unlock using the remote control. The downside to this is that the light will remain on for the timer's duration no matter what state the ignition is in. Let's say you have the timer set for 15 seconds, everytime you unlock the light will stay on for 15 seconds. So, if you unlock the car to get something out of it, and then close the door and try to rearm the alarm before that time has expired it may cause the system to bypass the door trigger, or even false, depending on how the system operates. The other downside is that if you unlock with the remote, get in the vehicle and start driving, the dome light will also remain on for the duration of the timer. This can be bypassed rather simply though by just interrupting the output from the 528T when there is energy to the ignition circuit in the vehicle. To do this add a relay and wire it like:

Pin 87a = Brown from 528T
Pin 87 = Output to domelight trigger
Pin 85 = +12V fused ignition
pin 86 = Ground

This relay will be energized the entire time the vehicle is running, so be sure to use a high quality relay.

Hope this is what you were looking for.

Hi Twelvoltz,

Thanks for your reply, yes it is dome light supervision I need.

I hadn't thought about if I unlocked the car to get something out and relocked it again the dome light would cause the alarm to trigger and false.

My alarm does work like that would there be any possible solutions to avoid this?

Also my central locking is controlled by a DM-1V Pneumatic/Vacuum Central Locking Car Alarm Interface which is triggered by the alarm unit's negative when armed output...would the wiring cofiguration you gave still work?

Many thanks,
Mo

MMH1] wrote:

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br>My alarm does work like that would there be any possible solutions to avoid this?

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I just read my post and realized that you could cut the trigger wire going into your alarm and put it to the normally closed portion of the 528T, trusting there is no spike it should work.

Just modify the wiring a little,to look like this

Cut the dome light trigger going into your alarm.

Yellow = Ground
Orange = To door trigger - input to alarm
Brown = To dome light - output to vehicle dome light circuit
Black w/stripe = To unlock output - from alarm
Black = Ground
Red = +12V Fused supply

This would provide a negative out to the dome light while the 528T is active, giving you dome light supervision and seperating the alarm trigger during the same time. It will restore the dome light connection to your alarm when the 528T is off.

MMH1] wrote:

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br>Also my central locking is controlled by a DM-1V Pneumatic/Vacuum Central Locking Car Alarm Interface which is triggered by the alarm unit's negative when armed output...would the wiring cofiguration you gave still work?

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Yes, the 528T activates it's timer with a - pulse input.

Hi Twelvoltz,

Just to make sure:

My car's door when openned supplies a negative voltage to my domelight via the door pins which are normally open.

The negative door trigger input of the alarm is connected to the door switched negative of the domelight.

My alarm outputs a negative when armed to the central locking module which locks the doors when a constant negative is received and unlocks when this negative is removed.

Does the second set of wiring instructions supply a negative when disarmed to give say a 15sec. domelight supervision and when the alarm is armed turns off the negative to the domelight (if before the 15sec. are up)

Thanks, Mo

I am not familiar with your alarm (and cannot find any manuals for that brand online) but most provide a negative trigger output for lock and a seperate negative trigger output for unlock. These outputs will stay connected long enough to drive the vacuum locking system. You would want to connect the 528T to the unlock negative output from your system.

If your system does indeed operate the way you are stating and does not offer the negative outputs with lock and unlock then you would just cut the loop on the 528T and use the armed output wire. If you read the manual, cutting this loop activates the unit when a ground is removed from the circuit.

Twelvoltz wrote:

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If your system does indeed operate the way you are stating and does not offer the negative outputs with lock and unlock then you would just cut the loop on the 528T and use the armed output wire. If you read the manual, cutting this loop activates the unit when a ground is removed from the circuit.

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Hi, yes it has no onboard locking output it is provided by a separate module.

I just looked at the instruction sheet and it just says: Leave BLUE loop connected for (-) trigger or Cut BLUE loop for(+)trigger.

Would it still work if the constant negative is removed (ie. when disarm/unlock is initiated)?

Thanks for your patience with a novice,
Thanks Mo

The manual shows that it can be either a - or + pulse to activate the timer.

Keep us posted.