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Old Aug 14, 2008 | 12:39 AM
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GEM/Door switch question

Ok, I am installing a new Compustar p2w900FMR/CM4000, it's a really nice remote start and alarm, in my 2002 F250 Superduty 5.4L. I have a problem with the interior lights and door switches, so when I tried to cheat and use the dome light for the door trigger on the alarm, it went off 30 minutes after the doors were closed and GEM went into battery saver.


So I decided I was going to tap each door switch at the GEM since I had it apart and would trigger off the rears doors (unlike the dome light.)

I found my wiring diagram, and pulled the correct wires (again, I've done this trick before.) So I wired it up with diodes to see what would happen, nothing in short. So I tested them. My first round I noticed that the voltages suddenly dropped. I kept up all of test and recorded them.Attachment 10773

This image shows my spread sheet of results. Notice how when I work (open and then close the latch) the door latch in 12B-15I (F12-G15 I worked the pass side latch) that the voltage is high and then drops down to what I tested the first time around. The voltage was high for 5-10 seconds and then my meter auto-ranged down. Is this normal?
 
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Old Aug 14, 2008 | 06:05 PM
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What does the alarm system require? The factory door switches ground when the door is opened I believe.
 
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Old Aug 14, 2008 | 06:28 PM
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The alarm will accept either polarity with a change in the jumper. It has a long polling time, so I am going to try it again tonight/tomorrow. While I am in there, I'd like to figure out what's up with my dome light/door ajar.

I have confirmed that the latches are sending the correct signal to the VSM, I tested my ground which showed a 0.001v potential to my door. I've got a good ground. Then I checked the four power wires I found in my chilton's manual, they all came back as 12.34v, so power is good. Does anyone have a diagram of the VSM that shows what all of the wires do? I'd like to see the out put of the VSMs door triggers to the cluster.
 
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Old Aug 14, 2008 | 08:30 PM
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Let's try this.
http://arrc.epnet.com/autoasp/framerq.asp

That didn't work. I sent you a PM.
 
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Old Aug 14, 2008 | 08:58 PM
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I have attached a diode with the cathode stripe on the VSM wire and anode on the wire going to the alarm. The alarm is set for (-) trigger. My remote shows the doors are open at all times. After Burn Notice, I am going to confirm the connection to the brain, and if it's right (as I suspect) I am lost and am going to have to call the manufacture tomorrow.
 
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