Firstly, forget what happened considering it necessity of the time.
In hot summers many T-valves start mal-functioning and create problems for engine.
You have already replaced the water body, that?s good.
Now try to find the T-Valve from Suzuki or from outside in market.
Bring your car to another good Electrician, and ask him to fix this valve and also put the fan in auto mode.
Meanwhile also check the Hose-pipes. If these are weak, then better to change them simultaneously.
Fill your car with simple water and run it for a week~10 days to check if everything is working smooth. Specially the level of radiator water, T-Valve working OK, Fan is at auto mode, etc..
If everything is OK, then you can choose to drain water and fill coolant.