door trigger isolation

[desitdt 10+ year member]

Hey there i have a 2000 ford explorer and im trying to isolate the door triggers for the alarm activation.

I have followed these steps but it still does not work:

The BCM is to the left of the radio. Remove the radio and then the two 8mm screws. The dash snaps right off. You can get lights and all triggers right there. I don't like the double diode isolation. I isolate all 5 triggers and then use a relay to trigger the alarm.

5 triggers to 85

fused 12v to 86

Ground 87

87a not used

30 to green wire on the alarm

Ive wired everything this way but it doesnt make sence.

Click to read more...

 

[keep_hope_alive Premium Member]

so when any of the door triggers pulls to ground, the relay contact closes and the alarm wire is pulled to ground. that is how it's wired.

can you hear the relay click when you open the door? are you sure the doors are negative trigger?

are you sure the alarm wire you connected wants to see ground. some alarms can have positive or negative trigger doors, and some have separate wires for each one.

 

[desitdt 10+ year member]

i think i just wired the resistors backwards, ive never wired a relay to work this way and im pretty sure thats what i did.

 

[keep_hope_alive Premium Member]

Resistors don't have polarity so you can't wire them backwards. Is resistors a typo? Did you mean the relay coil? That doesn't have polarity either. The door triggers may or may not have polarity depending on the trigger. Negative trigger switches just have one wire connection since the housing is grounded to the car body. Positive triggers have two connections that are isolated from the chassis.

 

[reallyxxxxloud 10+ year member]

I think he means Diodes... If the alarm sees a negitive trigger and the doors go to ground when opened get rid of the relay and just wire in a diode for each trigger...

 

[keep_hope_alive Premium Member]

yea, he probably meant Diode. good call.