I'm guessing that it's low on refrigerant, which would prevent the compressor from engaging. Have you connected a Manifold Gauge Set to check the static pressures?

The place to start would be to leak-check the system, as you suggest, while the system is still pressurized. Look for oily spots and/or traces of green fluorescent dye on all visible A/C components and connections. Also look for dye in the condensate that drains from the evaporators (under the vehic...

An ambient temperature of ~65°F is somewhat mild for testing system performance. Around 80°F or higher would be better. Regardless, based on your pressure readings, I agree that the system seems to have a leak someplace even though it's the rear A/C that blows cold. Do you happen to know whether the...

I want to follow up on the process and volume of getting PAG-46 oil into the system. I read the Toyota R12 to R134a conversion document http://tms.cleanautoalliance.org/documents/ac002t98.pdf and I think the oil volume described (100cc) assumes the system is not flushed (the process on Pages 5-6 do...

My guess is that the ambient temperature was between 75 and 80 degrees. Still, I'd like to see the low side a bit lower than that. Keep an eye on it. If the evaporator ices up, it might be a little undercharged.

OP, be aware that those small cans of refrigerant might contain fewer than 12 ounces. The only way to know for sure is to weigh-in each can (or partial can) to arrive at the total amount for your system.

One-quarter cup equals approximately 2 fluid ounces. So, yes, put 2 fluid ounces of the proper weight PAG oil back into the condenser.That's the amount I was going to suggest anyway.

Several questions here, but the first few are:
How did you evacuate it?
How did you charge it?
Did you check for re-heating?

Great news...thanks for updating us.

Both the high and lower pressure switches have been replaced and the refrigerant load is per spec as he had it evacuated and refilled to factory levels. Another thought: Depending on when it was evacuated and re-charged, it's possible that the system has a leak and the refrigerant amount is no long...