Yes bro, it's solved. It turned out to be a bad ECT sensor in the end. I verified by putting in a 220 ohm resistance across the two terminals of the ECT sensor connector and the temperature gauge moved mid-way as it should :). Btw, here is something else that I would like to know about the main fuse box:
I found that one relay in the relay box is bypassed and made direct. Here is a sample diagram for reference:
The upper relay out of the two encircled relays is currently set to direct. What is it for? I couldn't find about this relay in the service manual anywhere. Also, the second relay (the bottom one within the red circle) is missing. What are both these relays for? Do these have anything to do with the fan being direct? Or is there a possibility of a bad thermostat?