Printer Friendly Forum Posts - Alarm Interior Light Activation

I have a Dodge PU with aftermarket alarm, when the alarm is deactivated and the doors unlock the interior lights come on for 30 seconds, I have a handicapped person that needs more than 30 seconds to get situated and the lights go out too soon. Is there anyway to extended this time with perhaps a latching relay or some other means.

Thanks

well some alarms can be programmed with a latche dout put that can be controled through the remote and reset with the ignition and a bunch of different ways . what kind of aftermarket alarm is it?????? and if your alarm has no features like this then the answer to your question is yes you can build a latching relay to do what you want. posted_image

if you have the owners manual or installation manual you can check to see it's latching options and follow accordingly but post back with the brand of alarm and someone can help you.

Also could add an 0 - 90 sec adjustable timer ($20-$25)

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I'm Don.I can answer all your security questions. I have 12 years in the industry.

Its a Crimestopper CS2000 from reading the manual I do not see an option for programming the light to stay on longer, seems like 30 sec is the max.

Maybe want to use a capacitor to extend the time..probably need a big one depending on the amount of time you want the light to stay on....the following might help:

https://www.the12volt.com/installbay/display_topic_threads.asp?ForumID=3&TopicID=2319

but, i bet this can be done with a relay and a door pin also..but i dont know if you need light after the door is closed or what... and that might be a problem if you were to disarm your car and not go back to it for a couple of hours...the light would still be on, unless it had some kind of timing circuit on there...

SO....your best bet would be a capacitor or two if your alarm system can't make the light stay on any longer.

Anybody else agree? thanx.

Yup , I'll have to agree on this one ( any other takers ?? ). You can have the door trigger as the activation wire so that the relay stays N/O until the doors close and then the relay will shut off the power going to it. The capacitor will slowly drain and the light will dim out as the capacitor slowly drains. The cap will re-energize when the doors are open again and the cycle will continue.

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Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA

OK..i was reading some info on the net and got these measurements for a capacitor..

An 35WVDC electrolytic capacitor that you can get at your local radio shack:

47MFD will give you an extra 12 sec. (approx)
70MFD will give you an extra 20 sec. (approx)

You can play with the MFD ratings but the lower the number, the smaller the charge.
Also..I wouldn't go any more than 70MFD..thats alot of charge... posted_image

I am not that good with knowledge about capacitors so I am only posting what I saw...If any of these are wrong or it sounds like I have no idea what I'm talking about, please let me know..thanx! posted_image

An extra 20 seconds should work, but another question. I have been an electrician all of my working life but not very knowledgable in electronics, how would I wire the capacitor, what I have presently is a -trigger from the alarm that energizes the coil on a relay and allows a negative output from the relay to the dome light. The dome light has a constant +.

This all came about when the alarm was installed. Before that when the door was opened the dome light stayed on as long as the door was open. When the alarm was installed the installer disconnected the door activation because when the door was closed and the vehicle was started the doors would not lock, he claimed that the dome light which fades to off rather than just shutting off was making the alarm brain think the door ws still open.

Thanks

There is a positive and a negative terminal on an electrolytic (one of which will be marked). You need to make sure you get the polarity right when you install the capacitor. You'll want to wire the neg. lead to the neg wire of the dome lamp and the positive lead to the positive wire of the dome lamp..(NOW .. THIS IS WITHOUT A RELAY..I DONT THINK YOU NEED ONE IF YA DONT MIND THE LIGHT STAYING ON FOR THE EXTRA TIME DURING ANY DOOR OPENING/ALARM DISENGAGING..)

BUT PLEASE...dont install it until someone here will verify that this is they way you should do it...i dont want you to mess up your electrical system because I 'think i know what im doing'...hehe posted_image thanx.

I think you need a resistor to regulate the dischagre rate of the cap - and a diode to prevent the charge from going the wrong way- - BUT I COULD BE WORNG.

Whenever you are dealing with a capacitor of any value, you should really place a small ohm value resistor inline of the power wire to slow the charge and discharge of the cap. A diode is a safety precaution that you really don't need, but if it will make you feel safer installing it... it won't hurt anything, just takes more time.

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Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA

Hey Jeff,

Any small size resistor will do?

Thanx.

Thanks for the suggestions, will give them a try, will probably experiment with a seperate light before wiring into vehicle light

Play around with the resistance a bit. try about 800 - 1 k ohm and if this is too slow lower the resistance or raise it if it's too fast.

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Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA

sounds good gentleman...make sure you post the results! I always like to hear the ideas work. posted_image

Before I start I have been thinking that I may be approaching this in the wrong manner, the problem stems from the fading interior light, would it be simpler to find a way of shutting off the dome light when the door is closed instead of waiting for it to fade into oblivion ?

well, i know a 'stereo ON till door open' relay configuration is something like we would want but i cant seem to wire it correctly for this application...i run into the problem of having the door closed when disarmed (LIGHT ON) and opening it without having the light go off till door closed again...anyone care to try?? posted_image