this is driving me nuts i've found dozens of pinouts but my wires arent matching up with any of them. i have a 86 se v6 im putting a 3.4tdc this is how my pins are

a-orange
b-tan/black
c-black/white
d-light blue
e- dark tan
f-pink/black
g-yellow
h i think its a dark grey or brown
jlight pink/white
k-pink
l-brown/white
m-black/white
n-black/white
p-light brown or tan? and black
r- purple/ white

This is the source Ive always used
http://www.fieroaddiction.com/c203c500.html

There are a few discrepencies with your wiring, its up to you to test out those wires and see what they really do. It lists the function for each wire, so its easy to test, example, proble the tan\blk you have in "B" and see if it has 12v. You should put more priority on color rather than location, color is more universal across all GM vehicles by application, pin location can vary from year to year, or even more in just one model.

You can find my build thread in archive TDQ, should have the wiring conversion pin by pin in it.

C203
pin A is supposed to be for upshift light on manual trannies but i have fount wires in this spot on auto cars.
pin B is feed from the fues box to the fuel pump relay it has +12 volts all the time
pin C this is the service soon light feed to the dash and goes to the donor PCM MIL or SES out put
pin D this is +12 volts for the A/C that has gone through the pressure sensors in the front compartment it is used either to let the PCM know A/C is selscted or to control the A/C clutch relay
pin E is oil pressure gauge feed from the oil pressure sensor
pin F is +12 ignition feed to power the PCM
pin G is the speedo high feed to the speedometer
pin H is not used on most swaps it was the speedo feed to the PCM but most newer engines send the speedo info to the PCM directly then the PCM controls the speedo

Pin J is TBI inj fuse 1 feed to the injectors it is +12 volts ignition and on SFI engines it can power all 6 injectors
pin K is TBI inj fuse 2 feed which on SFI engines this can be used to power all the other needed +12 volt ignition needs on the engine
pin L this is the feed from the fuel pump relay to the fuel pump
pin M this is ground for the speedo just connect it to chassis ground
pin N this is 25 Amp feed for the A/C compressor clutch do not mix it up with pin M
pin P this is the TCC signal from the brake pedal on auto cars to let the PCM know the brakes are being applied
pin R this is the speedo low signal to the speedo which gets grounded on newer swaps using an auto tranny