My tape player has never worked so I pulled the mechanical part of it out. I would like to:
1) Bypass the circuit that lets the receiver know it's closed much like this guy on youtube did. Maybe I need to make a switch? Maybe not.

2) Strip wires for L, R, and GND to put in the aux port.

Since the tape deck has never worked I'm not entirely sure how to approach finding which parts need to have their circuits closed. Any help would be appreciated.

I will say I believe that the mechanical portion of the player had 2 bus attached. I believe the one on the left is for the controls and the pink ones on the right are for the actual audio feed as they are wired into where the tape would have been read.

Here's a link to the pics in g-drive

 

On the tape deck there will be a microswitch that closes when the tape is inserted, this will send a signal to the microcontroller to put the motor on and switch the heads to audio in,. Also some tape decks have a reel stop sensor pn the takeup spool which needs to be kept pulsing, then the microcontroller switches the tape off and back to radio.

So i would be looking to bypass the switch that puts the tape in,, As for inputting your aux signal, use the L R Gnd terminals on the Tape output pcb, (bottom left pic) terminals are on top right of pcb, which is also the pink connector on the main pcb bottom right.

 

I took apart the mechanical portion of the the tape player to pull of the board from it. I found several switches. There are 2 boards actually, one at the bottom where the tape would read and another at the top which is connected to 2 motors. I assume that top portion (left on the photos) is for controls like play and fast forward. This board has 2 switches and I'm not sure what purpose they serve but after inspecting I think they will open the circuit when a tape is not in the player.

The board near the where the tape is read (left side) has one switch. When I fidgeted with the mechanical portion of the tape reader it seems likely that this switch is then tripped telling the micro controller that that there's a tape in there.

Today, I'll be working on it with the controls exposed and actually physically depressing the switches as its on. I'll report back my findings. Wish me luck!!!

 

I actually soldered the jack in but I still keep getting an error message from the receiver. There's some thing wrong and it's not what I've done. I will say that I found the switch but I disconnected the ground from the board that was connected to reader of the tape. Perhaps the switch can't close the circuit b/c of this. Either way I've posted a car forum to get some insight into the Error code 8 I'm getting when I try to switch to the tape player.