#9063, "RE: AT/MT swap almost done, except for this little switch..." In response to In response to 4
I'm sorry. I must have left out a critical piece of information. There is one more connection to make. Here is the A/T back-up light circuit.
You have already used the reverse sensor to replace the park/neutral position switch. That provides power to the coil on the back-up light relay. Unfortunately, the other side of the coil needs a ground (previously provided by the TCU). You need to take the white wire with red stripe from the TCU (EATX ECU) and connect it to a ground. A convenient ground is the black wire from the transaxle range switch. Confirm that this works for you and I'll add it to the Wiki.