Fantastic Answer it seems , You seemto be on the correct side , but you should note that the transmission oil never gets hot if i donot use thr A.C.can afaulty A.,C,pressure vaulve also cause the Fans high speed relay not to activate ,and do you conclude that the heating transmission fulid is unrelated to the A,c, pressure vaulve or a fault in the thermo switch , I ask this as i have also noted that the fan opperates only on the slow relay the air given out by that fan seems very little
If the A/C is blowing cold, I wouldn't look at A/C components like a cycle switch or high pressure cut off switch. I would be looking at fan relays, fan wiring, fan PCM strategy. I would "active command" the fans using a Ford IDS diagnostic tool, or equivalent.
Have you checked for any restrictions between your condenser and radiator/transmission oil cooler? If there is an air flow issue up there somewhere, you could have some overheating like this. The fan, being that it is only blowing slow, is not helping.