While driving the engine shuts off when turning on blower fan for A/C or heat

It sounds like the AC compressor is locked up. to be sure can you please shoot a quick video with your phone so we can see what's going on?that would be great. You can upload it here with your response. Can you unplug the compressor and retest please? You can pull the relay that would be easier here is the location. Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.