06 Kia Sedona overheats when ac is on. If the ac is off the van will return to normal temps. Had the compressor just replaced and v-belt. Both fans appear to be running when ac is on.

Does the engine over heat or the gauge goes to hot. Really hot. Since the A/C is on , this puts an extra load on the engine. This is why the fans come on when the A/C is turned on. This is usually low speed fan mode. High speed doesn't come on untilll 220 to 230 degrees. Most vehicles. Cars don't over heat untill the gauge gets in the red, when it starts getting close is time to worry and stop. I guess the question to you would be, What does the temp gauge read?