Hope someone can't point me in the right direction.

I'm looking for a manual/information for what I think is a Goodman system. This is the info that I have. The air handler lists Goodman Manufacturing Co. The model # is A-36-00 REV D, Serial #9812402610. The compressor doesn't list the company name. The model # listed is BRC S0361BD. There is another number, 990910605.

I've attempted to email Goodman but the email was returned undelivered. I've tried to call but no one returns my calls.

The problem is that in the 90+ weather the system can't keep up. I've been told that the system may be too small for the house. It is a raised ranch w/ cathedral ceilings; approx 1270 sq. ft. The system is 3 years old. Also I've been told that the previous owner complained to the contractor about the system and then proceeded to "play around" with the system. So he could have screwed something up. For example, there are a few filters in the returns but they appear to be some sort of thick insulating material rather than a filter. I'm not even sure where the filters should go. These filters could be blocking the air rather than just filtering the air.

Also, when I checked the air handler I noticed that there is a cord coming out of it with a jack on the end (almost like a small headphone jack). Does anyone know what that is?

Anyway, I'll shut up now. I would appreciate any info or assistance on the system.