replaced ac compressor and accumulator, converted to 134A, still no cold air

'89 F150 - replaced ac compressor and accumulator, converted to 134A, still no cold air. I think I need to replace orifice tube or expansion valve after following up a bit more. (Haynes book isn't the most comprehensive of course.) If I'm on the right track, I believe I have one or the other, not both. And I understand I may have a "blue tube" or "red tube" orifice. (I believe that's what my system has, not expansion valve??) If I do have an expansion valve, where is it located?? If orifice tube, which one?? It's a 4x4 with a 5.8l motor, auto trans.,XLT Lariat (if that matters). Appreciate any help you can offer. I guess I should break down and get a real shop manual.

ANSWER:
Have you checked pressure low and high,it will let you know if you are having a blockage,due to debris clogging the orifice tube screen. This is a common problem when a compressor fails You have no expansion valve, the orifice is in the Evaporator inlet, to get it you must discharge the system and disconnect the line. You can switch to the blue orifice or get a variable orifice tube . You then need to evacuate the system with a vacuum pump,and charge to 80% of what is stated on the label for freon capacity when it used with R12.Here is a chart that shows the pressure readings you should have.If you have a blockage,the low side will be low and the high side higher than normal. Hope you get it fixed,it sounds like the orifice is the problem,here is a link that shows what it may look like,and how to go about fixing it, you may have to copy and paste to your browser http://www.ackits.com/merchant.mvc?Screen=CTGY&Store_Code=01&Category_Code=BlackDeath