I need some help. I installed a python 990 alarm in my 07 gt. I can't get the dome light supervision to work. I have the relay hooked up like this.85 to alarm d.s. wire,86 to 12v, 30 to ground, 87 to -lt.green/yellow car dome super wire. Any ideas. The relay does work.

 

you have it wired for a negative trigger door right? I have not had my head inside a new mustangs guts as my shop only gets imports. If they are neg trig then bypass the relay and connect the alarms domelight supervision wire straight to the door trigger. What you do with this is tell the car that the door is open, and it turns on the light for you(using a factory relay). I have been installing for almost 15 yrs and done this a million times.

If your car has a positive trigger door locks then your relay should be wired,
86 to alarm output(neg output)
85 to +12v
Those two are your switch.

87a - not used(insulate as it is hot when the relay is not triggered)
30 - dome light/pos door trigger
87 - +12v

 

I have the door triggers wired negative. I used the -alarm door trigger and split it to both car -door triggers. driver side -lt.green/black. Pass. door -yellow/lt.green (I had to use two diodes to keep my alarm from falsing)

I tried it and it doesn't work. I think my alarm brain is messed up or something. The alarms -black/white dome super wire only drops like 1.3v instead of going to ground.

I think I am going to try hooking up the -disarm,rearm wires from the alarm to a relay to turn on the dome super. Do you know how I could set up that relay. Could I have both -disarm, and -rearm going to the same relay pin?

 

the diode isolation that you put in is preventing it from working then. Even if you use a relay, if you want the door triggers to turn on the dome light you will need to make that connection to the factory door triggers after the diodes you put in place.

Diodes are simple little things that allow a dc voltage signal to go in one direction and not the other. You had to use them to isolate the doors from each other but that isloation is preventing the signal you want to go back into the car, and turn the dome light on.

 

I figured it out, my alarm dome super wire is bad, its not going to ground. I probably fried something inside the brain of the alarm. So I am going to replace the brain and hope that fixes the problem.

 

are you sure you are testing it right because if you didn't make the connection after the diode it will not matter if it working? It would showground after disarming the alarm for 30 secs.

Where did you buy it from?

 

Ya my alarm brain was bad. I fried something when I was experimenting with the dome super wires. I just swapped the brain out, and it works fine now. Thanks for the help.