engine light issue

[jarred c brider]

Hi i replaced my motor in my vs comm with vy engine and replaced all the usuals,(sump,inlet and exhuast manifolds) and im having an issue with the engine light and engine fan coming on after about 10 seconds of idle. I had it scanned and it come up with a fault in the temp switch so i repleced both switches under the thermostat housing with no success. Also tried the fan relays. Any suggestions of any kind that could help me fix the problem??
Thanks