Ok so I bought an AutoLoc/ Stellar alarm and shaved door kit. Its two components, the alarm control unit and the add on 18 channel control unit to control the doors along with what ever else I wire up. I've go the two units wired up and working but I don't want to carry two remotes. The instructions for the kit say you can wire a relay up to leads soldered to the remote switch and control the remote buttons with a channel on the add on unit. I want to do this but I don't want to worry about the battery in the "wired in" remote going dead. The battery for the remote is an A23 12V battery (data sheet on the battery). My car battery is 12V, why not wire it to the car? So here's the delima... I soldered leads to the battery post of the remote and tested it using the car battery, it works. I soldered leads to the button on the remote and tested it with the car battery, it works. I wired the switch leads to a relay switch and triggered the relay with the old remote battery, it works. I wire the remote to the original remote battery and trigger the relay with the car battery, it works. I wire the relay to the car battery and the remote to the car battery and it fries the button and that button will no longer work. I've tested this on three buttons so far and it happens that way every time. WHY? I don't get it... What am I missing?

Pictures of the front and back of the remote.

Front

Back


Hi rez front Hi rez back

Ok, I think I got it. I put a diode between the 12v power to the relay and the neg signal to the relay. Put another one on the pos input side of the remotes switch and a 330ohm resister on the output side of the switch. It hasn't fried yet, the other buttons fried with one try, and I've given this one around 50 so far. Hopefully it will keep it up.