Overheating problems with my 1993 Toyota Corona EX

I have a 1993 Corona with 2.0L, 3sfe engine with overheating that took me about 5 tries to fix as it was a combination problem with the Fan system.1> I fan was slowing at random; found that out when I stopped. This was the fan closest to the battery. the car on an overheating condition and the fan was barely turning 2. There are 2 radiator/coolant thermostat switches. One is at the bottom of the radiator by the AC compressor side. This switch goes to ground when the coolant is hot. There is another switch, of different color, in front of the distributor area, NEAREST to the engine block - this is a "second" fan system that was not mentioned in my Haynes Service/repair manual( there are 2 to 3 sensors there). This is by the return hose area and measures the "Hotter" coolant temperature.This turns on the fan also.. This switch on my car was corroded and fell apart when I unplug the connector. also, a mechanic in the past ( this is the philippines) professionally joined the wire to this wire with a tight twist:so after 26 years this electrical joint was no good. I SOLDERED it. Also there is a heater RELAY ( better described as a "Radiator Fan ON" ) in the engine compartment fuse box, this was bad (intermittent failure). So this was the final fix...but a week later one of the plug hose cap burst...no heater here as it is in the Tropics...;) :) :) NB: Going back to the sensors in front of the Distributor again; the one closest to Engine block is the Heater/Fan switch..it is a different size, color and shape than the one on the radiator. The second senor is the active Engine temperature measurement and has variable resistance to heat: ..