ref toyota hi luxe van

Wanted to add another sensor to a Toyota van apart from door triggers, wired a single zone prox to the dome light in the cargo compartment, wired to separate ground 12v+ and door trigger via a blocking diode. It works but not enough juice to trigger the alarm. Right I'll add a mini relay (I make my own same as DEI 8616, but with a diode across the coil). Now it brings on the dome light BUT when you arm it it triggers the alarm! It wasn't doing that before I added the relay and it only does it when the dome light supervision has shut down and the dome lights are extinguished. N.B> There's already a Clifford G5 dual zone prox in the front that's been there some months. Any thoughts?

you might have to isolate cargo lamp wire but i think you have the diode reversed . might not need diodeabethebue

I had the problem before I inserted the diode, it didn't change anything, next I dioded the power feed in case it was coming through the bulb. In fact it even happens when I remove the bulb! This vehicle has separate trigger circuits, one for front doors and 1 for rear, but I noticed the front dome light came on when I opened the back doors, wonder if I screwed up the original install a year ago?