r3dfish

I am installing a car alarm into my 99 DX hatchback, and am trying to hook up the Dome Light Supervision wire, which everyone says to hook up to the door trigger. The problem I'm having is all the wiring diagrams I found online say the Door Trigger is a light green/red wire on the Green OEM Alarm Plug, which is located in the stereo bezel to the right of the steering column. I can't seem to find the OEM Alarm Plug on my 99 DX. Is there some other place that I can tap the Domelight Supervision wire?

Also, I can hook the Door Trigger wire directly to the domelight wire (when I figure out where that is), but does the Domelight Supervision wire need to be hooked up to a relay?

TiNuts

It's been a long time since I've installed an alarm (and never in a honda) . . . Door trigger should go to the door trigger itself. If the domelight is switched to not come on with the door open, the alarm may not see the door open.

I've never personally used domelight supervision, but iirc you should use a relay.

r3dfish

I have found the door trigger wire in the drivers kick panel, and I have tested it with a multimeter to verify it is the correct wire. The problem is that it only hooks up to the drivers door switch. I would like my alarm to trigger if EITHER door is opened, not just the drivers door. I cant seem to find where both of the door switches meet. Everyone seems to say they're in a green OEM Alarm Plug in the car, but I can't seem to locate that plug in my DX.

Former User

The Grn and Lt Grn/Red wires from the driver's and passenger's door switches run to terminals B9 and B8, respectively, of the integrated control unit that plugs into the rear of the dash fuse box.

r3dfish

I want the door switch to trip if either door is opened, is there any danger to bridging B8 and B9?

TiNuts

EDIT: actually, after looking at the drawing RonJ posted, you should be able to just tie directly to the passenger side door trigger (B8) and that will cover both doors.

r3dfish

Awesome,

Thats exactly what I needed.

Thanks for all your help, you saved me a lot of time.

EDIT: ok, I'll give the passenger door side a try. Thanks guys.

TiNuts

You should put a diode in between the door trigger and alarm like my drawing. There may already bee one in the alarm circuitry, but just to be safe. It's to protect your alarm from the domelight voltage that comes in to the door trigger wire.

Former User

Couldn't he just splice the alarm into the Grn wire for the driver's door switch? This way no diode would be needed because there's already one present in the integrated control unit.

And isn't your diode drawn in backwards? Maybe I don't understand how the alarm talks to the dome light, but I presumed it would provide ground for voltage to the dome light and turn it on.

TiNuts

The diode you're talking about in the icc will prevent the alarm from seeing the passenger door open. As far as I can tell, that diode is to isolate the beeper (key in ignition or lights on beeper?) from going off when the passenger door is open. If he wires on the passenger side, it will see both doors.

No, my diode is correct. It's to isolate/protect the alarm from the domelight. The domelight circuit will put 12v on the alarm, which is more than likely not a problem, plus the alarm probably has one in it if it is necessary. I just put it in there to be safe and doubling them up won't hurt anything. My diode is in there for the same reason as the vertical diode coming directly off the beeper.

Mainly I'm trying to prevent "Hey you told me to wire this up and now my alarm is fried!"

My drawing,etc is solely for the door trigger, which you don't necessarily want the alarm to talk to the domelight as the doors opening/closing still control the domelight. If he wants domelight supervision, then that's a different circuit, but my diode still applies.

TiNuts

This is how domelight supervision should be wired in, again if I remember correctly. It's been awhile.

Terminal 86 on the relay may need to be wired to +12V instead of ground if the alarm uses a negative trigger.

r3dfish

For now I have gone ahead and wired the green wire in the drivers door switch to the alarm. This is a temporary fix. Here is why:

If I sit inside the car and activate the alarm, manually unlock the drivers door and open it, the alarm goes off as expected.

The problem is if I sit inside the car and activate the alarm, manually unlock the PASSENGERs door and open it, the alarm does NOT go off.

Everything I have found on the internet says to tap the light green/red wire at the OEM alarm plug. I could be wrong, but my 99 DX Hatchback doesnt seem to have the green OEM Alarm Plug inside the stereo bay that everyone is talking about. I thought I had found the other end of this wire at the fuse box, but after testing with a multimeter, It was not the right wire. I am going to have to spend some more time this weekend trying to figure out where I can tap into the passenger door switch, or if tapping the dome light would be easier.

Former User

Okay, that makes sense. I didn't understand what the alarm supplied to circuit. Apparently, it supplies (+) voltage to the circuit and uses the voltage to know when the door is opened through grounding by either door switch.

Former User

I think you'll get the desired result by splicing the alarm into the Lt Grn/Red wire near the ICU, as TiNuts has suggested.

TiNuts

Right.

r3dfish

I tapped the light green/red wire that comes out of the plug in the image and that solved everything. Both doors now set off the car alarm. I did not use a diode.

Thanks for all the help.

Now to put the interior back together ...