The short answer is... Yes.
Why? Because.... (severial reasons go here and they'll vary depending your situation.)
So you say the compressor went out?
If the pervious owner didn't want to spent over a $1K then he just replaced the compressor. The receiver/drier must be replaced anytime a system is changed over. The expansion valve [located in the high pressure line on Gen IIs] and the condensor should also be replaced at time of retrofit. When the compressor whet out, particles from it likely went throughout the a/c system. They must be cleaned out or poor opreation and repeat failure are near 100% sure. After somewhere in late '91, a more effecient condenser began showing up in the GenII (made to work with r134a) even though they still used r12 in most through '93. This is newer model condensor, designed for r134a, has many more and much smaller tubes in it so it could much better remove heat from the refregerent. The problem could be that particles from the compressor-gone-bad may have plugged (blocked) some or many of the condensor tubes and reduced it's ability to remove heat.
Unrelated to compressor failure would be the problem of the old receiver/drier unit with old oil from the old r12 system. It mixes with the new r134a and r134a compatable oil after the retrofit and an acid is created. Depending on the health of all the components and how much you run the a/c, you'd have 3-months to a year (maybe 18-months) of working ok then complete failure; not if - but when. This is also the case if the old evaporator core, condensor and lines are not flushed (cleaned) out good. You can't clean out a receiver/drier; gotta change it out with a new one.
The expansion valve could be a problem for either of the same two reasons above. Ford, for some da#& reason, decided to hard-crimp it into the high pressure line at the end nearer to the condensor. It should have been located close to the entrance of the evaporator core at the fire wall lower port. As a result, many people notice the high pressure frosting up --- which means the freon is absorbing heat from the engine compartment before it even gets into the evaporator --- further reducing system operating effeciency.
If the system was converted correctly, it's possible some of the condensor tubes could be blocked or it has an older style condensor that's just not good enough to pull the heat out of the R134a. A correct retrofit (IMHO) is replacing everything except the evaporator core and it must still be flushed out good. Most people are gonna get quotes from $1000 ~ $1300 for that. To do it your self on a GenII is about $500 in parts + vac & charge.
Ok, sorry for the long winded response. :banana: :banana:
