Adding AUX input to OLDER OBS Radio/Cassette Radio

[Kable]

I seen the sticky of install an aux input on a newer style delco. I been trying to tinker with install one on the older style delco radio/tape unit....



These are the three piece radios.
Headunit with the clock and controls that connects to the "main unit" under the dash
And the tape deck that connects "main unit"

The tape deck has a 9 pin connector
Tan- Data
White- Audio
Red- Audio
Black- Ground
Orange- Power
Blue- Data
Gray- Illumination
Black- Ground
Black with Blue Stripe- Power

I simply cut the White and Red and hooked them up a female audio jack with a ipod hooked to it.
Instantly the radio kicked off and the ipod started playing thru the silverado speakers.
So i cut the Black/Blue and the ipod kickeds off and the radio comes back on.
So i know i need to wire that to a switch to switch between the two input.

The sound quality like this wasnt bad. I had to turn the volume up to hear the ipod.
I could leave the setup like this but i think im going to add a small multi speaker amp or some sort of internal amp to get better sound quality out of this set up.

So my next question is has anyone done this?
And does anyone anyone have any suggestions to adding an amp internal or external?

[1990GMCSIERRA]

ive never seen this done,pretty cool tho

[Kable]

I just figured out how to add a preamp to it as well. Super easy. Cost for the preamp is about 12 dollars. It just conditions the signal for the amp.

I hate the way after market units don't fit the interior of my trucks. Ill finish a full write up soon as i get the new preamp in