2000 grand prix, false trunk hood trigger

Hello. I'm having a problem with false trunk-hood triggers on a 2000 Pontiac Grand Prix. I installed a Autopage RS-727 alarm system. I installed diodes in line with the door pins and trunk and hood pins, but the problem persists. I tried reading other forums trying to find out how can I solve this, but I'm still confused. What other thing can I do to solve this? Is this a problem with the alarm or the vehicle?

Do you have seperate inputs for all the triggers. ie hood trigger, trunk trigger and door triggers on the auto page unit

Hood trigger and trunk trigger use the same wire on the alarm. Both are diode isolated. Door trigger also use the same wire on the alarm and are diode isolated too. The hood is a separate wire from the trunk pin wire. For the doors I used the driver door wire and the other 3 doors wire. All were diode isolated.

Question: do all of them trigger properly right now when you open each door, the trunk, or the hood? If any of them don't I would say you have a diode reversed.  If they all work properly I would suggest cutting each input one by one until the falsing stops.

In your first post you say you have diodes in-line - do you mean inline from the doors/trunk/hood to the alarm? or inline between the door switch and the BCM on the car?

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C Renner's Auto Electronix
My service is cheap, quick, and good - pick any two

Yes, they all trigger properly when I open each door/hood/trunk. The diodes are inline coming from the door/hood/trunk wire to the alarm wire.

OK...what you'll probably have to do is diode isolate one or more of the door/trunk triggers from the car. 

To do that - connect diodes inline between the door or trunk and the BCM. The striped side should be facing the door or trunk, and the connection that goes to the alarm should be on the striped side.

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C Renner's Auto Electronix
My service is cheap, quick, and good - pick any two

OK. I'll try that and post back the results.

Here's what I did. I checked all connections, checked all diodes, and they're all ok and the diodes facing the right direction. I'm still having the problem. The diodes are installed on the wires coming from the pins to the alarm, cathode facing towards the pins. When alarm triggers, it displays on the LCD of my remote that zone 2 (hood trunk),was violated. What else can it be?

You need to also install inline diodes between the BCM and the point at which you tap into them. Some GM "W" body cars have a tendency to send a small pulse from the BCM down the trunk/hood and door pin wires. Cut all the inputs for the BCM from the hood, trunk and doors and install diodes inline with the band facing away from the BCM. This will stop any BCM pulse that is triggering the alarm. If this fails, then you have a bad switch on affected trigger circuit. The only other way would be to install your own dedicated switches that only connect to the alarm.

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sparky

I can try that, or can I try using the domelight as the trigger? Wouldn't be that easier?

If the false trigger is occuring from the trunk pin, hooking the wire up to the dome light won't do anything. Many GM vehicles may not turn on the interior dome lights if the ambient light inside the car is high. Some cars sense this and don't permit the interior lights from coming on. Many GM vehicles have a switch that bypasses the interior light. If you hook to the dome light wire and have the switch off, then the alarm won't go off if a door is opened. Many alarms can't handle a delayed dome light and will sound an alert if the dome light is still on when you arm the alarm.

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sparky

OK. My car is not equipped with that feature. It turns the interior lights as soon as I open any door during the day or night. My alarm has the 45 second door delay, so I activated it.

Here's what I tried; I cut the trunk pin wire and left the hood pin wire on. No more trunk/hood alarms. Also I cut the door pin wires and connected the door zone wire coming from the alarm to the negative wire of the domelight. The result was false door triggers. I tried adding a diode inline between the negative of the domelight and the door wire of the alarm, getting the same false trigger. I left the door wire of the alarm off and didn't get any false alarm, just in case the problem was the alarm itself. I think that the problem comes from the car. What else can I try?

Follow the instructions in my earlier post. You must diode isolate all the door pins from each other and from the BCM. You need four diodes for this. Two to isolate the doorpins from each other and two to isolate each door pin wire from the BCM. You also need to do the same for the hood and trunk pin. Therefore you need 8 diodes.

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sparky

OK. Thanks Sparky, I'll try that and repost the results.

Let's see if I get this straight. I'm drawing on a paper how is this supposed to go. You say I should cut the tan wire and put a diode with the line facing the BCM. And do the same with the dark blue wire on the other side. And on the door side, that's the side contrary to the diode's line, I should strip the wires (tan and dk. blue), put another diode with the line facing the doors and hook that wire to the alarm's door trigger wire? Is that correct?

The inline diodes' stripes should be facing away from the BCM, not towards it.

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C Renner's Auto Electronix
My service is cheap, quick, and good - pick any two

You mean away from the BCM in the tan and dark blue wire of the car or in the wire that comes from there to the alarm or both?

Yes. The band in the diodes that go inline in the tan and blue wires between your alarm and the BCM should face away from the BCM. If you get it wrong, the dome lights won't come on with the door open.

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sparky

The stripes should also face away from the alarm input, and toward the actual door switch.

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C Renner's Auto Electronix
My service is cheap, quick, and good - pick any two

Go to the download section on this site and search for "1076". That diagram should explain everything.

OK. I get it. I'll try this tomorrow and post the results.

OK. The file that JWorm pointed me to helped a lot! I did what you guys told me to and so far 5 hours have passed without a single false alarm. All doors trigger when I open them. Everything is working fine now. Thanks everybody for your help. Hope this help someone else too!