I bought a used Hummindird 360 and it came with a heading sensor. I don’t think it’s a gps I think it’s just a heading sensor but I could be wrong. It has two wires coming out of it a black and a red. So humminbird said I needed a AS HHGPS. I got the cable and hooked it all up. The heading sensor has a clear button that briefly lights up when the unit powers up. The unit doesn’t show that there’s anything connected. I called humminbird customer service they didn’t have a clue. What have I done wrong or what do I need to do to get the heading sensor working? I’m connecting the 360 and the heading sensor to a 999ci hd si. The 360 has been working fine.

Never heard of what you described.
The AS HHGPS is a cable to connect a handheld GPS unit or AIS to a Humminbird, that is what the description states.
https://www.humminbird.com/sites/humminbird_site/files/hum_productmanual_ig_ais_helix_532458_0.pdf

The original 360 in all three versions--transom, Fortrex, and Ultrex comes with the AS GPS HS puck.
It is included so you can MARK and DISPLAY waypoints on the 360 view.
That puck is still a current accessory and not included with the MEGA 360 but is needed for the same purpose as with the original 360.

Minnkota has a puck that is a Heading Sensor only and has Minnkota on top of it. It talks to the Minnkota iPilot via Bluetooth. AND can be shared to a Humminbird unit IF the iPilot is the LINK version and the Ethernet cable is attached between the iPilot and Helix.

Thanks Wayne P. The heading sensor i received does say Minn Kota on top. I didn’t even realize it. That makes more sense now I was given the wrong thing with the 360. I guess I will be in the hunt for the correct as gps hs puck now. Guess buying that adapter wire was a waste of $30 bucks.