Maker Pro
Maker Pro

ford GEM, detect if door is ajar

mike webb

Jun 3, 2017
1
Joined
Jun 3, 2017
Messages
1
greeting all,
i have a 2003 ford mustang, inside her is a thing called "GEM" (generic electronic module). it does all kinds of stuff but the thing that is does that interests me is that it can detect when a door is ajar. it does this in the following way. each door has a switch which runs directly to the GEM (pins 7 and 8). When a door is open, the switch in the door is closed, sending a ground signal to the GEM. The GEM in turn (via pin #9) illuminates the "door ajar" lamp on the dash. pins 7 and 8 are interesting because thru them i can tell which door is open while pin 9 would only tell me that a door is open.

so i got this i/o device from measurement computers that has 3 ports of 8 bits each (24 inputs or outputs) uses 5 volt ttl logic to determent if a switch is on or off. I'm wondering whats the best way to hook up pins 7 and 8 from gem to the i/o device. i would think that i could place relays between pin 7 and 8 and when the door is open the door switch would close and that would send 12 volts from gem into the ground, it would pass though the relay and intergize it, that would close the switch and a 5 volt line could send a "on" signal to the i/o device.

if i blow up gem that's a couple of hundred dollars to replace, if i blowup my i/o device that's a hundred dollars, if i blow both of them up..... so i think it wise to ask for help and guidance.
 
Top