I'm putting a new headunit in my 1990 V8. This is a Pioneer to replace the one that had replaced the original headunit long before I got the car. This one, though, at least has red lighting!

Along the way, I need to replace the antenna. You see, there was a good reason the antenna that my car came with did not retract: the mast and tube from the original power antenna had been broken off and simply screwed into a bracket against the inside of the trunk! Stupidest thing I've ever seen. (Well, okay, maybe not THE stupidest thing...)

A friend scavenged me a Hirschmann Auta 5091 power antenna from a V8 in a parts yard. No idea if its original Audi equipment or not. He did not bring me the Hirschmann relay.

In my trunk, there are a couple of chopped off electrical leads right behind the ex-antenna that read a constant 12V (key on or off). One is blue-red and the other is white. I believe these are the leads that should have been hooked up to the antenna. There is, however, no third lead to serve as the trigger the antenna and line up with the Hirschmann yellow trigger lead.

Question is: can I hook my head unit trigger to the Hirschmann yellow trigger lead... or do I need to put this on a relay?

Thank you!