Cirrus, AC & MPGs

[flagmanruss]

With the HOT weather, I've really needed the AC (bad things happen to my MS if I get over heated). The MPGs totally tanked... and it seemed the AC was working but not really cooling the car very fast. I decided that I ought to drop the kick panel (includes passenger's side duct or I would have left it off) and drop the blower & check/clean out the cage & ductwork. I had trimmed the tab on the console side of the kick panel last time so only the duct holds it on there & just a ribbed plastic push lock on the right, grab & yank. 3 screws & 1/4" drive rachet drops the blower motor. There wasn't as much in the cage as I expected. I reached in & got a couple of small handfuls of debris, leaves & a little bit of insulation (mice ought to be running out of that stuff as I have removed all I can reach). At least there was no actual nest & no mice, dead or alive. I can barely reach the heater core & I tried to get any crap out of it by hand. I was able to barely get the end of the shop vac hose into the duct with my hand & turned down toward the bottom of the heater behind the resistor block. All together a wad about the size of a soft ball.I can reach up through the duct & feel the outside air / recirculate flapper (seems to be mechanical & works fine). I wish I could get into the cowel to screen the opening to keep the critters out. Now yesterday was not as HOT but I had to lock the car up in the Sun while I shopped & it seemed hot when I got back. I felt the car cooled much quicker and colder so I had to turn the AC down. My conclusion is that the AC was running all the time because of inadequate air flow... which neither cooled the car nor allowed the AC to cycle, wrecking MPGs. Then came the reassembly. One really needs 2 functioning hands to hold the blower motor up & start the screws. Unfortunately, my left side pretty much doesn't. After quite a few attempts & more choice verbage, I scrounged a 2x4 which I laid across the threashold & used my body weight to lever the motor to stay while I started the screws. Mission accomplished.I'll keep you posted.Russ

[Mopar1973Man]

Actually a properly running A/C unit should run constantly on a hot day and never cycle. Now cycling on a cool day is normal because the low side pressure is low or the low side temp is getting near freezing which will cause the compressor to cycle out. The whole idea is to get the evaporator near freezing without letting it freeze because as it cools the humid air it would freeze up and quit blowing. So yes in if its a mild day it should cycle in and out but a seriously 100-120*F I expect it to run constantly and never cycle because the evaporator will never reach freezing temps.

[flagmanruss]

Well temps here were 90-95 humid degrees... with the direct Sun on a closed car, the temps inside just soar. Even when opening all the windows & trying to blow all the heat out... I think the hot metal & trunk just heat it right back up.On our house, our nephew just installed 3 new attic powered vents... twice what the square footage calls for... about 1/3 down the roof slope. (Yes, we had a gable end powered vent... which didn't cool enough. Switched to soffit & ridge vents without power, still the problem persisted.) We don't have AC in the living space... yet. Before we could blow cold outside air with a huge window fan through the house from our bedroom. But one can't sleep in a wind tunnel & soon after shutting that fan off, the room temp would rebound because the attic was unbelieveably hot. Since the new vents were installed, the vents shut off soon after dark (staggered set between 90-95). And the room temperature does not rebound noticeably. We can reduce the temp to just above outside temperature... depending on what that is & how much humidity... Our nephew has offered central air at cost, when their work slows down... gotta do it.Russ