AC stopped working, engine light on, coolant spill

While driving, my AC suddenly stopped working. About a half mile later my check engine light came on, and the thermostat dropped all the way down to the "cool". There was a burning smell. I had the car towed home, and the bed of the tow truck had anti-freeze all over it from my car. I'm concerned that this is linked to a major repair done a month ago as the result of flood damaged, which included a used engine replacement, manifold gasket, intake plenum gasket, rear main seal, oil filter, spark plugs. Any idea what may be wrong with it, and if it can possibly be related to the previous repair?