Kenwood KDC-2025 – Purpose of Blue Wire?

[Kirdud]

Hello Captains!
I just started upgrading my stereo to a modern unit. While disconnecting my existing Kenwood KDC-2025, I noticed a plain blue wire. It was bundled in the same plastic sheath as the power cables (red, yellow, and black), and it was connected separately near the antenna through a plastic connector.

According to the manual, there’s no mention of this wire or connection. I checked some similar wiring setups on eBay and found others with the same configuration—so it’s clearly not unique to my case.

Could anyone help identify the purpose of this blue wire?
Thanks in advance!

 

[makomark]

From what i found, the Blue wire is NOT used on that model.

 

[halbrodmann]

Blue wires on a stereo traditionally are used to power an external amp or a power antenna in a car/truck. The blue wire usually has 12v when the stereo is turned on.

 

[Kirdud]

According to the manual, the blue wire or blue wire with a stripe is related to the antenna or is not used, but this only refers to the wires with the connector. The question concerns the separate blue wire located near the antenna connector. The manual does not mention anything about this standalone wire.

 

[Kirdud]

I finished the investigation that weekend. That cable is related to the remote controller. Maybe it will be useful to someone.