ej888

Hey guys, I have a pager alarm and want to add a hood pin switch for additional security. I want this pin switch to activate the door trigger input but ran into a problem. The problem is on the main harness connected to the brain, I see the door trigger inputs have two wires, a "Green (-) Common Door Input" and a "Violet (+) Common Door Input". Are each of these wires connected to each door of my coupe? Can I use a tap in squeeze to piggy back to either one of these wires? I don't want this hood pin switch to activate the "Blue (-) Hood/ Trunk/ Aux Trigger Input" because I want to save this for my battery backup and I kind of consider the hood a "door". Any input is appreciated.

fcm

You will only use the "Green (-) Common Door Input" the violet one is for pos.(+) triggered doors, your coup is neg.(-) trigger.

Use your blue hood pin input for the hood pin, and the trigger output from your back-up batt., if your alarm does not have any more neg.(-) inputs, connect the trunk trigger and anything else to the blue also and use diodes to isolate them, you can install as many neg.(-) triggers to the blue as you want, you can't "use it up", the door trigger on most alarms have other functions then just triggering the alarm, sometimes for, programing, valet modes, passive arming and so on, best to just connect doors to it. 94

ej888

Thanks for the quick reply. I think my alarm only has 2 negatives not including the 2 stage shock sensor. "Blue(-) that combines hood/ trunk /auxiliary"(I assume I can connect the hood, trunk, and anything else to this same blue wire?). Last, the "Green(-) Common Door Input". I'm a little confused, so should I connect the hood pin switch to the Blue wire, then use a tap squeeze to piggyback on the Green wire for the battery backup? Would you recommend wiring it that way?

ej888

I just re-read your post. So I should connect the battery backup and pin switch to the same Blue wire. I looked up "diodes" and assume you can get them from radio shack and what do you mean by isolate them? For example, do I solder a diode to battery backup output wire and solder another diode to the pin switch wire, then solder the opposite end of the two diodes like a "T" to the blue wire? Thanks.

fcm

The diode will prevent a signal from one sensor going to another sensor, so each sensor trigger lead needs a diode on it cathode end, [end with strip] to sensor side, then all the anode ends, [end with no stripe] can be connected together and then connected to blue lead, the hood pin switch lead does not need a diode as it has no load to feed back to, the trunk pin on the other hand, does need a diode as it has a load, [trunk light].

It is very important that the trunk pin gets the diode, the ground output trigger from the sensors is a "low current" ground and if there is no diode on the trunk pin the sensor that is triggered will turn on the trunk light, [supply it with a ground] but because the trunk light needs a lot more current then any sensor can provide, the sensors trigger output will be damaged.

Read... http://www.the12volt.com/diodes/diodes.asp 94

ej888

Thanks for the information. I used paint to draw a diagram, could you tell me if this is correct? Also for the switch you said there is no load so a diode there is optional. Does this apply to the battery backup too? I assume the battery backup only sends a signal and no load.

fcm

That is correct, the only one that does not need a diode is the hood pin switch. 94

cpncpn

Thanks for this information. I was looking for something similar to this for my car.