The local Nissan dealer has no clue.

The air conditioner deposits an oily film on the inside of the front windshield and rear back light. This film is very resistant to ammonia and alcohol based window cleaners. This film is not ethelyene glycol based. The heater system does not deposit the film.

Questions:

What is the source of this film? AC seal lube?

What is the best way to clean this film off the glass?

How do you stop the ac from depositing this film?

Is this film hazardous to human health? One can only imagine that you are breathing this stuff as the ac is busy depositing the film on the windshield.

Thank you.

 

Your car is a 1993. Your evaporator is probably filthy dirty. Road grime, diesel exhaust, tar, pollen ect ect ect. It all gets in there as your drive with your HVAC system on. You need to get in there and clean it out.

http://www.keep-it-kool.com/treat/treatment.html

That should solve your problem. Read the how it works section.

 

Thank you for the tip. We will look into it... I wonder though, if it is diesel grime and road tar, Why is does this film tend toward a milky white consistency, as opposed to black? I have lived in downtown Chicago, and know very well about diesel grime from the busses coating everything in the apartment!
Thank you.