First, when retrofitting only fill the system to 80% with R134A of what the R12 capacity was.
Electrically start by checking for power at the A/C compressor connector DB/BK wire with the connector unplugged and A/C on. Then check to see if the ground(BK wire) is ok. If power and ground are ok your problem is in the clutch coil,if the compressor was locked up the clutch would still engage.
If no power is present start at the A/C pressure switch (on the Expansion Valve, aka.H-Valve on the firewall R/S).Check for power on the DB/OR wire with the A/C on(power is supplied from the A/C-Heater control unit).If power is present jump the pressure switch connector and see if the compressor engages,if so replace the pressure switch. If the switch checks ok check for power at the A/C clutch cutout relay(L/S fender),Power in is on the DB wire and the BN wire, power out to the compressor is on the DB/BK wire, the ground side of the relay is controlled by the LM on DB/OR wire on the Blue connector cavity #3.If you have power at 2 sources and ground is ok but no output replace the relay.
If power is ok and no ground you will need a scanner to see if the controller is seeing the request for A/C.
If you can get ahold of a scanner you can actuate the relay thru the scanner.
Fault code 33 is for the A/C clutch relay circuit.
If TPS voltage is too high you will not get A/C, the controller disengages the compressor thru the relay at WOT conditions.