there is a delay unit in the A/C wiring of this car, it induces a half second delay to the A/C compressor to start. The reason Honda installed it was that it takes about half a second for the vacuum pod on the carburettor to raise rpm when the A/C compressor starts. With the delay unit working you cannot ever feel the A/C compressor start when the car is idling as it ramps up rpm and the half second delay starts the compressor in effect catching on the uprise and stabilising the rpm. (you may notice other carburettor car engine shakes a bit as the A/C kicks on - not this car)
If your temperature needle does not go above that C mark then there is no thermostat in the engine (this engine takes an 82C thermostat originally), install it as without the thermostat there will be very poor coolant flow into the intake manifold and also very poor engine performance and very short engine life. Also make sure to remove all air from the bleed nipple that is on the thermostat mounting flange.
for the wiring - remove the battery and its tray and undo all the stupid BS wiring that your electrician has put in, the original wiring is more than enough for this purpose, a total of 4 wires come to the radiator, two are thick they are for the fans (one from relay bridge and one is a body ground bolted near the right parking lamp)
the other two small wires are for the thermoswitch - one is body ground and one goes to the coil side of the relay. If your fuse box is melted out then you can either undo that relay socket and replace it (not everyone is upto that task as its called -meenakaari ka kaam) or undo its wiring from the socket clips and mount a relay outside the fuse box. In first case you have to remove the whole fuse box and carefully open it up. In the other case you can tap the wires as they exit the fuse box.
The wiring on this car is very very easy, dont sweat it.
