Air conditioning not blowing cold unless the lights come on

This usually happens when the compressor clutch coil shorts out intermittently. Here is a guide to help you change out the compressor, but I would test the compressor relay as well.

https://www.2carpros.com/articles/replace-air-conditioner-compressor

and

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Check out the diagrams (below). Please let us know what you find.

Cheers