2007 Honda Civic engine fan not functioning/ dashboard ligh

Hi. My honda civic matic got flooded up to its dashboard. We followed that necessary protocols for flooded cars (dont start, change oils, etc). The car was able to start and run BUT the lcd on the dashboard that shows the temperature guage, speedometer and gas guage is blank and is blinking a red light (it was originally yellow). We thought it was a minor probllem so we drove it around and it overheated, turns out that the engine fan is not functioning at all (but the fan linked withe A/C is functioning). My dad said the control that transmits signals for the fan to operate when the engine temperature is up is busted. Had it checked with a mechanic/electrician and he said the IMMOBILIZER has to be replaced. I'm confused. Arent immobilizers for alarms and security purposes? What do you guys think? And what does the blinking red light means. Please I need a more expert advise. Thank a lot.
PS. Btw, we had the fan connected directly to the battery and it worked. Just doesnt work when driving and is not attached to battery anymore