Check engine light it comes on when I turn the blower or fan on?

It sounds like you have an alternator that might be bad or the blower motor is pulling too many amps. We will know for sure if you run the codes to see which ones are stored. Please go over this guide to help you see which codes they are so we can fix the car.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Here is the blower motor location in case you have a low voltage code. Please go over this guide and get back to us.

It just shows what needs to be done to check out the problem so you have an idea of what the repair will entail. This code should not have anything to do with the blower motor.

The P0705 code on a 2007 Saturn Vue indicates an issue with the Transmission Range Sensor (TRS) Circuit.

Could it be that the blower motor operation is just a coincidence? Just it has the problem each time you turn the blower motor on, can you please shoot a quick video with your phone so I can tell for sure what's going on. You can upload it here with your response.

Lets clear the codes and try the blower motor again to see if the trouble code comes back.

I don't think the blower motor will make this code, can you try it again without turning on the blower motor to see if you get the same code?

The fan motor must be causing turbulence in the electrical system, I would replace the blower motor and then clear the codes, please let me know what happens.