Thanks for the add.
I am installing an UNGO MS8200 car alarm in a 1989 VW Vanagon (with factory power doorlocks). The VW system requires a 12v+ trigger for both the "lock" & "unlock" circuit which are 2 different wires.
The Ungo lock trigger wires (2) provide a negative ground signal at all times EXCEPT momentarily they provide a 12v + when either armed or disarmed (1 wire provides 12v when armed; the other wire provides 12v when disarmed). After the momentary 12v+ either circuit returns to providing a constant negative ground signal. The locking system in the VW doesn't like this. I guess my question is:
How do I wire in relays to maintain the 12v+ momentarily but delete the constant ground signal that the Ungo brain is outputting?
Any help on this is appreciated! I have tried relays in several configurations but haven't found one that works. The Ungo manual makes it seem that the system should output a 12v trigger without relays but it's the constant -gound (I think) that's throwing me for a loop.