Yeah I might be biting off more than I can chew here, but I'd like to learn how at some point. This is definitely my backup option, but I'm at least gonna give custom wiring it a shot. I might just open it up and go "no way in hell" and go buy an A/S shifter somewhere. I will give it a fair shot first though.
1. The TCM doesn't know which shifter you have in your car. Except for '98 MY, the cluster is what tells the TCM (or PCM in '02 and up) that the car is A/S or not. IOW - if you have an A/S cluster in, the non-A/S shifter in '3' position will put the tranny in A/S mode (the TCM simply looks at the position that the range sensor is in - it doesn't know how it got there or what kind of shifter put it there). So - you can stay with your non-A/S shifter. Neither of my Concordes have A/S shifters, yet I use A/S all the time (using Puttstick - but you can do the same thing without Puttstick, using switches - see next point).
This is what I'd like to do.
2. Once you've got it in A/S mode (A/S cluster plus A/S shifter in A/S position or non-A/S shifter in '3' position), the up or down shifting is done by momentarily grounding the up shift wire or down shift wire. So yes - you can do the shifting in A/S mode by installing momentary switches on the up and down shift wires.
This is what I suspected. I think I get the concept now. If the cluster detects that the shifter is in whatever is after Drive, it will put it unti A/S mode. While in A/S mode, when the momentary push button switch is being pushed, it connects the Shift Up or Shift Down wire to a ground wire, and that sends the signal to the TCM. So one connection on the Shift Up button would be the Shift Up wire which runs to the TCM. On the other side, is the ground wire. When they're connected (i.e. the Shift Up wire is grounded by pressing the button in) the TCM reads that and shifts up.
Would it be possible to use one ground wire for both the Shift Up and Shift Down?
3. Your non-A/S car may or may not already have the up and down shift wires brought from the TCM into the cabin (C106 connector). No Concorde ever came from the factory with A/S, yet my '99 LX had the shift wires already run to C106, and my '98 LXi did not have them already run to C106. If yours does not have them run, you would of course have to add them into the TCM connector and run them into the cabin.
OK, I'll check for that tomorrow then. Did your car already have the ground wire installed as well?
So what I'm looking at here is this now:
I need to get and install a A/S Cluster.
The A/S Cluster will automatically detect what would have been 3 and L as A/S.
Then I need to check for the Shift Up and Shift Down wires. If there are none, I need to wire them from the TCM to the cabin.
Then I take the Shift Up and Shift Down wires, and wire them each into their own momentary switch.
Then I need to wire a ground into each of the momentary switches. So now when the switches are pressed, the switch wire gets grounded and tells the TCM to switch gears.
Then I need to wire the ground to anywhere in the car that's grounded? I'm assuming I can splice into an existing ground for this...?
Then it's good to go?