Here is the followup to my questions about which junkyard car to pull time delay relays from. https://honda-tech.com/forums/honda-crx-ef-civic-1988-1991-3/poor-mans-universal-%2420-car-alarm-system-relay-3141311/

So I now have a circuit that works exactly how I want it to. This afternoon I installed it in my civic, and so far it is working perfectly. However, use at your own risk. There may be better ways or better parts to create this circuit/design, so please feel free to leave specific helpful advice.

The basic circuit is completely "dead" when the toggle is turned to the OFF position.
The basic circuit is still completely "dead" even when the toggle is turned to the ON position.
The basic circuit will activate all the components ONLY IF the door is OPENED AND the toggle is turned ON. This means that even while the system is technically "armed", NONE of those 4 components is "active". This means that the battery will not be drained, unless of course the door is opened AND left open. If the door is opened (while "armed"), the circuit will be active (Beep the horn) until the door has been closed for 15 seconds. If no one shuts the door, the battery will drain overnight.
SPECIAL NOTE: I have not tested this circuit for long-term "triggered" (horn honking) state. My only worry is that a component might overheat.

Parts needed:
2x basic relay (to invert the input and output signal polarity) from many cars/trucks
1x Dodge/Chrysler "Key Light Delay Relay" (other options available in other cars)
1x Dodge (or any make??) Flasher Relay

So here it is:

 

So my understanding would be that the alarm will trigger if the door is left open after 15 seconds?

And this will just keep the horn engaged?

 

No. This design will "pulse/honk" the horn from the time the door is opened until a minimum of about 15seconds AFTER the door is closed. Even if the door is opened and shut again within 1 second, that 1second "trigger" will cause a 15second alarm. The alarm ends 15 seconds AFTER the trigger is removed. So if they stay and start stealing, the alarm will stay on. Or if they leave the door open when they run, it is going to go off until someone responds (owner/cop/neighbor/etc) and tries to "shut it up" by closing the door. It will get someone's attention.

It's not perfect, but it will be very effective against the sneaky thieves. The kind that want to steal quietly in the night. As for the "smash and grab" thieves that are hooked on drugs, no alarm in the world is going to stop a "smash and grab." Even if they figure out that the alarm goes off 15 seconds after the door is shut, it will make it effectively let everyone in the neighborhood know that something is wrong.

A simple "when door is opened, honk the horn full blast" design could be installed with the use of just 1 relay and a toggle switch.

 

I guess I'm stupid but I read this twice and still don't get it. Could you please explain exactly the arm/disarm/situations that will set off the alarm?

Here is how I'm understanding it: Park car, arm the system by flipping a toggle switch. If somebody breaks into your car and does not disarm the system by flipping the toggle switch within 15 seconds of them opening the door, the horn will start honking.

Is that correct?

 

This is how to operate. It's not perfect, but it's better than nothing. Just make sure no one knows where your secret toggle switch is. It's best to have the toggle switch hidden under the car, or in the grill, or behind a bumper. To prevent setting it off when you are getting in, you want to be able to turn off that toggle switch before opening the door.

1) Turn off car.
2) Get out and lock doors...same as always.
3) Covertly turn on the toggle switch.

Now.....if someone opens your door (even for 1 second and then shuts it), the horn will Beep/flash for a minimum of 15seconds. It will continue to Beep/flash until the door has been shut for 15 seconds because: Once the door is shut, it removes the Negative door-trigger signal......then the round chrysler/dodge delay timer will turn off in about 15 seconds. Once it turns off, the Flasher Relay will no longer send the flashing/beeping signal to the horn.

To get in the vehicle:

1) Turn off toggle switch.
2) Unlock doors and get in and drive away happy.

By turning off the toggle switch before opening a door, you prevent the Chrysler/Dodge delay timer will never activate the Flasher relay for 15seconds (minimum).

I have drawn the schematic as simply as it can be drawn. Follow the arrows to see how one component (starting with a Negative door trigger signal) activates the next component. The horn is controlled by the Flasher relay, so it beeps instead of a continuous honk. The Flasher relay is controlled by the Chrysler/Dodge delay timer, which stays operational for about 15seconds AFTER the door is shut.

Once it warms up to atleast 50 degrees outside, I will go out and get video so I can upload a demonstration.

And before anyone says, "Someone can just turn off the toggle switch and break in,".....Yes, I am aware of that. That is why it is important not to let neighbors/etc see where you are turning the toggle on. Put it somewhere that you can casually activate it....such as by kneeling to tie your shoe. For $20, including junkyard relays, wire connectors, wire, and a toggle switch, do you expect the security of Ft. Knox?? This is a basic system that will alert you if some crackhead has broken your window and is stealing your items or your whole car. It's up to you to make sure you hide the toggle switch somewhere that can't be seen, and make sure you don't let anyone notice that you are turning on a toggle switch.

 

I am not sure if you can see this video on Facebook, but I will post the link to a benchtest demonstration. Basically, you will see me SIMULATE a door-trigger for about 1 second.....The flashing lightbulb SIMULATES the horn. The lightbulb stops flashing about 15seconds AFTERRRRR I "close the door".

EDITED: deleted link to my facebook.

 

this is very very cool, thanks for sharing your design

 

Thanks for the support. I just recorded a video and sent it to my email. I will try to send it to photobucket so I can share it.

***Special note: The output can also be wired to operate the lighting simultaneously with the horn. I left that out, so the basic "alarm" is functional. The addition of 1 more relay can be used to behave in one of several options (headlights or cornerlights, flashing while honking or solid-on while honking)....all depends on what you want to happen.

 

Here is the video. Click it to play.

 

If the basic circuit is wired as shown above, then the flashing output can be spliced as shown in this picture: The flashing negative(-) output will now flash/honk the horn...AND...trigger another added relay that will allow 12v+ voltage to flash the lowbeams.

Just as the basic circuit above is designed, this relay is ALWAYS off unless the circuit supplies the negative(-) trigger. So there is no risk of this relay running down the battery unless the alarm is going off for a long period of time.

 

Your a smart cookie, wish I could figure this out

 

for whatever reason.. i can't see the video.. only sound..

 

I had this issue when I first uploaded to photobucket, but I reloaded it a couple of times and then it played fine. I don't know what the issue is or what the proper fix is. It may require you to install a MP4 codec, because it is a MP4 video.

 

Got to thinking.

You can wire your entire circuit to the ignition.
If ignition is ON then circuit is dead.
Use an additional 15 sec delay and wire it so when key is removed, then 15 sec later the alarm arms itself.
The toggle can be hidden on the interior as a defeat/valet switch or removed completely.

 

I've had ideas like that, but I need a basic relay that works opposite of common relays. Common relays are "normally off, but trigger activates." I need to find junkyard relays that are "normally on, but trigger deactivates (opens the circuit)." If I can find those in the junkyard, so many more options will be available.

There is still a few dollars left in the $20 budget.

 

You just need a 5 pin relay that has a normally closed contact. Pretty sure Ford uses them, or you can get universals at the auto parts store.

 

yeah usually pin 87a or whatever is the opposite of 87, as in NC vs NO contact.

 

Would you be able to be a bit more specific on where to find and what vehicles these relays are found in or are they really that simple to find? I don't know if I want to tear through a few vehicles to find them. Not that it's a lot of work but others are probably wonder the same thing as well. Great project and cool alarm though!

 

This is the delay timer I used. It stays active for roughly 10-15seconds AFTER the trigger-signal is removed (ie, the door is closed again). I found it on mid-1980's>>>>mid1990's Chrysler & Dodge cars. I am sure if you Google the part number (2889565) you can find a list of vehicles that it is compatible with (which means it may have one in it). I found them in the in-car fusebox on the driver's side.

The Flasher Relay and the 2 basic relays can be found in almost any car. Most cars have half a dozen or more basic relays in the engine-bay fusebox. The flasher relay I used is mostly from Dodge Neons/Stratus/etc. It is in the driver's side in-car fusebox.

http://www.ebay.com/itm/ACCESSORY-DELAY-RELAY-CHRYSLER-2889565-/200757446631?pt=Car_Audio_Video&hash=item2ebe1387e7&vxp=mtr#ht_6890wt_917
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This is something I Googled for 30minutes during my research and never found a basic wiring diagram. On newer Dodge cars, there is also a headlamp delay off (about 90seconds, I think). I have pulled about 20 but haven't tried to use them yet. :D They have 5 pins: 3pins are parallel to each other (stacked on one side), and the other 2pins are perpindicular (1 in middle and 1 on opposite end of relay).

The pins are shaped almost like: E l l
except the letter "E" above represents 3 parallel pins that are NOT connected by another pin.