I changed my IAT sensor today to get rid of my check engine light, and now that the light is out the heater won't come on at all. if i unhook the sensor and the light comes back on the heater works normally. a few weeks ago i unhooked the battery and the check engine light went out for about 15 minutes and the heater wouldn't work but as soon as the light come on the heater started blowing. Has anyone ever heard of anything like this happening? or know how to fix it?