The nice thing about this radio is that there are a lot of options to use switches that aren’t ever used. Who uses the 9 to 19 switch? You can use them for talkback, toys, mods.
Most of the two position switches have six pins. When the switch is in the up position there is continuity between the two center pins and the top two, in the down position it is between the two center contacts and the bottom two pins. You can verify this with your voltmeter, hook the black lead to ground(frame of radio) and carefully touch red probe to each of the contacts and record the voltage. You can also take photos with your cell phone.
Bright/Dim switch- On the bottom of the switch there is a unused tab, if you put your voltmeter probe there you will notice that when the switch is in the dim position, there is voltage there, how easy is that.
Channel 9 switch is upBlank yellow
Brown black
White orange
Disconnect all. Solder black and orange together, heat shrink, now radio is in 40 channel position and you can use the blank switch, run 13.8v into the center contact and hook the output to the top terminal on the same side.
CB/PA Switch/ wire Pa to talkback/up is PA
Brown yellow
Orange red
White black
Disconnect all check for power in, solder Brown and Orange together. Radio is now in cb mode. Run a wire from resistor on pa/cb jack to the center contact of this switch and run a wire back from bottom to other side of jack in rear of radio.
Note: when there is a switch with no black wire:
Solder Brown and Orange together to get receive
Solder Red and Yellow together for the meter.