6 disc cd player

[1978 paul]

hi i trying to wire up a 6 disc dash cd player i have the optics but am left with the 3 wires red black and yellow can anyone confirm the correct wiring, is red +, black ground, and yellow signal, don't want to just try and damage it.
many thanks

 

[EDZ649]

Yellow is usually wired to a permanent live but don't hold me too it

 

[Chattonmill]

Yellow is usually wired to a permanent live but don't hold me too it

What the permenant live....

 

[gIzzE]

I would guess the red is 12v, black is ground and yellow is probably illumination.

The changer gets its signal to turn on over the most bus ring.