Unit is original fedders from 1972. Gas heat/elec air. Condenser mounted on roof. New thermostate from power co. (they have not started their savings program yet) replaced both motors within last 5 years, along with caps, and the 24/220 contactors. Redone most of the wiring, both above and below. Puts out (or did during winter) plenty of hot air. This year temp of cool air is mid 50s when its 100 out, so the air coming out is colder than the neighbors new unit. Seems like the main vent, (the biggest diameter and only one in living room is not putting out enough air to cool that part of the house. Lack of $ means I have to keep babying it along. Any and all thoughts would be appreciated. And yes I laugh at it myself so humorous coments cool with me. I sure would like to resolve b/4 the real heat begins here in Las Vegas.

Give the duct work a good going over. Some may of come loose or choked off.

Thanks, Not looking forward to crawling up in the attic, with of course old fashioned fiberglass insulation. Any tips for spotting leaks? Attic is about 4' and the ductwork is flexible silver tubing sitting about 1/2 buried by the insulation which is loose and is about a foot deep

If you had a real smoke generator that would work well but you can turn on the unit and feel around the duct. Also check the air filter and the evaporator coil.