Go up on the roof
If you are able to do so climb up on the roof of your unit with a #2 Phillips screwdriver and a digital camera or notebook and pen so you can get the manufacturer, model and serial number of the unit. Remove the screws (there may be 4 or 6 around the base of the plastic housing) holding the cover on the AC and carefully set it to the side. Take a picture of the name plate and post here in the forum or provide the manufacturer, model and serial number from the nameplate under the unit cover. Please, please, PLEASE make doggone sure the unit power breaker is OFF prior to going up on the roof. We don't want you to be up there and it decide to cycle on. I'm attaching a photo of my nameplate sticker as a reference for you. Click on the "Attached thumbnail" and it will provide a larger view. With the model and serial number we can provide some more detailed assistance.
Chris in Virginia
2006 Sunseeker 3100SS/LTD
2008 Smart Passion Cabriolet TOAD
1986 Honda Helix (Original owner)