Hello. I have a Motorola Spectra astro siren hooked up to a hln1241d dek and Motorola apx 6500 radio. I searched internet and really couldn't find an explanation to what the pinouts on the dek are assigned to. I have a red wire coming from pinout 17 which is wired to a momentary switch which activates siren. I'm looking to find which pinout is for the air horn. Thanks for your help.