Toyota Repair: 93 Camry V6 (3VZ-FE) overheating question, summer weather conditions, coolant recovery

Question
Ted, I have a 1993 Camry with the 3VZ-FE 3.0L V6 engine. It blew its head gasket about two years ago. I had my mechanic install a quality used motor from Japan that apparently had only 25,000 miles on it. It overheated about 5,000 miles later on a hot summer day in stop-and-go traffic with the air conditioning on because, I later learned, the hydraulic fan was not spinning at high speed as it should have under the circumstances. I did not notice the overheating until it red-lined. Coolant bubbled furiously in the coolant recovery tank and out on to the street as I let it cool down at the side of the road. My fan was spinning very quickly when the previous motor blew its gasket. I took it to a Toyota dealer to diagnose and they determined that the power steering temperature sensor was unplugged. I strongly suspect that the mechanic who replaced my motor never connected this connector. As I was only driving it short distances in the city, it took until a year later during a summer highway drive that I learned that this motor has a similar problem with consuming coolant. The motor now probably has more damage. It now seems to only overheat and consume coolant after driving about 10 miles or so in the current summer weather conditions (with the heater running full-blast as I am trying to preserve the motor). I have put a complaint in with the better business bureau with the premise being that the motor which now has only about 41,000 miles (about 16,000 more than the 25,000 it already had) would be workig today if my mechanic had connected that power steering temperature sensor. My mechanic claims that the connector must have worked its way loose. What do you think the probability is that he connected that connector but it somehow worked its way loose? I would hope that Toyota designed it to not disconnect easily, along the lines of the way a telephone cable won't disconnect from a wall jack without squeezing a tab. Also, given that it does not seem to consume coolant on short trips of a few miles, would a compression test likely demonstrate that it has warped heads, a weak head gasket, or whatever the problem may be given my description? Given that it seems to not consume coolant on short drives, I am concerned that a compression test might suggest that it is fine (i.e. if the problem is related to the aluminum heads and cast iron block that only shows up when it is hot due to the different heat characteristics of the metals). What are your thoughts?

Answer
The engine can be checked for a possible internal combustion leak by doing a chemical block test, the dealer can do this for you it's more reliable than a compression test. The connector for the pressure solenoid that controls the fan does have a release clip like almost all electrical connectors that toyota uses, if the connector is not clicked on all the way then it may work it's way loose, of course the probability that is wasn't connected is also there, what was the toyota dealer's opinion on this? It should be pretty obvious if the connecter was not connected at all rather than just backed off.