Hello everyone

I have a 1992 Honda Civic DX hatchback with a standar 1999 engine, 1999 transmission and a cold air instake.

3 days go, after I start the engine out of no where, it revs at 2500 then slowly up to 3200, then drops to 2200 revs up to 3200 every seconde. My engine overheated, when I turn the heat on, it doesn't blow hot air out of the engine. The radiator fan doesn't work.

I didn't do anything to it lately, the engine was changed 4 years ago and the tramission this summer.

I changed the anti freeze and the thermostat yesterday. It didn't work.

Since the fan doesn't work, I think it may be the relay or the radiator. Anyone has any idea?