Electrical Failures

It was raining hard one day and I was driving my truck (1998 Ram 1500) through water that came up to rim height. Not long after, my stereo stopped working. Although power was still active (lights working), no sound is coming through. I have also noticed my cruise control is not working and my temp gauge max's out and the check engine light comes on. The temp will drop back down to normal in just a few seconds, which makes the check engine light turn off as well.

Now I am sure the temp issue is caused by my thermostat. But why the stereo and cruise control does not work is a mystery to me. I have checked all my fuses and they are fine. Any other suggestions of things I can check?