Actually, I guess the topic itself makes it clear that this is not a T question....
When I drove to Columbia a few weeks ago for the meeting with Garrett at Kent's shop, I had an experience I have never had before. I was driving a 2008 Mercury Sable and the temperature outside was in the low 80's. The distance was about 115 miles.
For the first 80-85 miles, the A/C worked like a champ - it was blowing cool air and I paid no attention to it. Then I began to notice that the blower wasn't producing anything, and the temperature in the car was starting to climb. Turning the fan to high didn't help - no air being blown by the fan. The small amount of air coming out of the vents because of the motion of the car was cold, but no blower.
In Columbia, I must have spent a couple of hours parked - first at Kent's shop, then at his place nearby where I had lunch with Kent and Kathy. When I started for home, the A/C was working like a champ again, and continued to do so for - again - about 80-85 miles. Then the same thing. Since then, in short runs around town, it's been fine.
So what happens to the blower that causes it to shut down after 80-85 highway miles? Any knowledgeable car A/C guys care to chime in?
Dick, I would first check the engine coolant, a lot of these late models will shut the a/c down when low. Also a faulty heater resister can cause problems. Check your electric cooling fan, it should run any time the a/c is switched on regardless of engine temp. heater relays can cause trouble. Good luck, some of this late model stuff is hard to track down, nothing is simple anymore. KB
Actually I thought it was going to be T related.
There is at least One nice Model T that has a very cool A/C unit in it. Now don't say it's not nice because of that.
Often if the freon gets low the evaporator will freeze over and the ice blocking the evaporator will cut the fan air to almost zero. Park it and the ice melts and then the blower will blow again.
Next time it happens while driving leave the fan on and turn the compressor off. The blown air should increase as the ice melts. In high humidity area like here in Florida, you will actually see fog (condensation) coming out of the air vents as the ice melts.
Check your freon pressures
Good luck
schuh
My dually does that when it's low on freon. When it quits, look under the hood and I'll bet you see ice where it's frozen up. When you stop or turn it off it thaws out and works again until it freezes again. Mine has done that a couple of times a year for the last several years. I put a sealer in mine about 3 years ago that was about $35 for just a couple of ounces, but it's slowed the leaking to something I can live with and delay spending the big bucks for a proper repair.
You might check your A/C clutch cycle switch, if its not cycling it will freeze up after a long period of time like you are describing. It is the switch screwed onto the accumulator. The switch is cheap and prone to failure.
Dick,
I have had that same problem on Ford Interceptors. The '99 and '07 was a corroded connector at the blower motor. The rest of the week it would work again when the hood was slammed closed. The '01 problem was caused by a corroded connector at the fan speed switch.
In all cases a new connector had to be spliced in.
Dick,
Bring it over. I'll check your freon level.
Steven
Hi Dick, The drain maybe plugged. The water cant get out and will freeze over the evaporator. When you shut it off it will thaw and then work till it freezes again. Clean the drain, blow the dirt out of the evaporator and all will be good again. Mike you need a dryer in your dually. Scott
I don't know if I've said it on the forum or not but I'm an Electronics/HVAC interested kid, so I know a lot about them.
I doubt this has anything to do with your refrigerant (Freon) charges. It's probably something outside of that, but I doubt it has anything to do with the refrigerant charges.
Like Steve Miller said, it could be a bad connector, or like Jeff Cordes said, it could be a failed switch. Anymore, units are prone to failing, so it can be anything.
If you have a low refrigerant, it could be a refrigerant leaks. I recommend personally to go to an auto repair shop and have them look at it because refrigerant leaks are very serious as older refrigerants can cause a lot of harm to the ozone layer in our atmosphere. The ozone layer is our only "defense" from the sun's Ultra-violet rays.
Low refridgerant switch's only purpose is to save the compressor. (have not used freon for years. at least not in Canada)
The blower fan is completely independent from the a/c system. It can push around cold or hot air and not care which.
Dick, did you try the fan with the switch in the vent position? Bet it did not work.
Is the fan running but not blowing air?
Is there an abundance of water under the car when you park?
These are two symptoms of an iced up evap.
Fords are famous for clutch wear and thence the clutch gap is too large for it to click in reliably.
The clutch cycling system may be malfunctioning, or just plain doing what the system is telling it to do (like it's froze up). I don't remember if your car has the variable wobble system, but that is, in effect, the same as the cycling system.
It needs a bit of diagnosing. Your system has R-134a.
I use R-12 in my T because I think is requires less pressure and thence less HP to operate...just my theory. The new condensers do a good job with the R-134a pressure problem. R-12 has gone by the wayside and isn't available any more.
The OZONE hole is theory comparable to the global warming theory. Some believe it and some don't.
Were you running with the A/C set on "Fresh Air" or "Recirculate? It makes a difference in regard to the A/C forming ice, especially in your part of the country where there is often lots of humidity.
A simple way to determine what's happening:
When it stops blowing air just pull over to side and turn on the heater full blast. Shortly you will probably see a large amount of water drain from under the car. This demonstrates that the evap coil is iced up. Simple fix after it thaws out is to just run the fan at a higher speed.
I learned this when my son and I were driving to CA from Arkansas a few years ago. He likes to run the AC unit at max but turn the fan down to a lower speed. When we quit getting any cool air I tried the above procedure. Worked fine from then on.
Dick
It sounds like your getting the dreaded "Icing Up" failure.
Many things can cause it - with low refrigerant being one.
Just don't destroy the Ozone layer -
I'd hate to be fried by ultra-violet rays or any ray - such as X, Y, and Z rays.
They could ruin my weekend plans to take the T to get ice cream or make me sterile.
Dick:
You definitely have evaporator freezing over shutting off the air flow thru the evaporator. It could be low charge, but most likely is a partially stopped up orfice tube. Either case, you should be experiencing a "fast cycle" of the AC compressor clutch. Restrictions of this nature are always signified by a "cold frosty spot" in the high pressure line from the condenser to the evaporator. This line should normally be hot to the touch. As you know, these late models are really tight under the hood to get to anything. I would recommend seeing a good Ford dealership.
Good luck
Roger