Quote Originally Posted by tonymy01 View Post
You can certainly use a double pole relay, which has two separate circuits it will switch, and put your car switch on the relay trigger (switch to, say ground with 12V connecting to relay input). This will cause the relay to trigger and for a dp relay, it will allow you to switch two independent circuits.
that will work. but I would imagine youre transmitting on the same frequency (or pretty close) but two different codes and they may be drowning the other out.