In MAX, recirc mode the AC should be about 36-42* especially on a mild 75* day.

 

Mine was 45 at 92 degrees the other day.

 

Now it's worse. I get some cool air from the passenger side and hot air on the dirvers side and little or no air in the back seat vents. Any suggestions?

 

Sounds like you have a ducting problem, or your heater core valving doesn't shut off all the way.

 

Is it the mixture valve or the little soleniod/motor that moves the vents?

 

I wish mine got that cold. I had mine in to Ford about a month or so ago and had it checked and a line replaced and refilled and now on the freeway it gets down to 48, better, but low 40's sound nicer.

 

It would have to be the the solenoid since Ford has routed the hose from the top of the thermostat straight to the heater core. If you can't get that door shut, then you'll pull heat from the core, and cold air from the evap. If you try to block the heater core by installing a gate on the inlet hose, you'll blow hoses off after a while unless it's tee'd somehow to bypass the coolant flow, allowing circulation. I'm going to play with it this weekend, and see what I can come up with because I'll be bored.

Stupid idea, but it's fixable. My only concern would be from coolant sitting inside the heater core not circulating...I'll have to see what the internal core is made of before attempting a bypass.

 

My A/C and heat work intermitted. My Dodge mechanic friend suggested that I disconnect the battery for about 5 minutes to let the system and the valves recalibrate. When I start the truck back up, I have A/C so cold it will turn your lips blue. The problem is that I have to do it every day at some point to get my A/C working again. Any ideas why this is?

 

Hi Guys,
There is an ongoing thread on the 'other' forum regarding the lackluster overall performance of the AC in our 04-08' trucks (members in the South and Southwest are especially vocal on this). A member (Spoonergooner) figured out that HOT H2O/coolant from the engine is continuously flowing through the heater core. Apparently there is a very thin plastic sheet that separates the heater core from the AC core under the dash. The radiant heat from the heater cores warms up the AC (notice how much warmer is in an AC house in the kitchen if the oven is on?). Spoonergooner got a 10 degree decrease in temp at his AC ducts with a simple mod. A lot of members on the f150 forum have seen similar improvements using his mod. The mod is quite simple:
1. Go to HD or Lowe's and buy a 1/2" ball valve with nipple ends (a 3/8" valve works as well) and some hose clamps.
2. Cut the hose that leads from the the top of the thermosatat (Spoonergooner has pictures) and insert the nipple ends of the ball valve in to the heater hose ends that you just generated by cutting.
3. Install hose clamps.
4. Turn ball valve to "off" position.
5. Start truck and voila 10 degree Colder air!!

Before Ford starting maximizing cost cuts, all heater/AC systems had a valve in-line with the water/coolant line that would stop coolant flow to the heater core and prevent heat build up when running the AC. Usually this was vaccum operated from the AC switch, so that when AC was being used, the flow to the heater would be turned off. The ball valve solution of Spoonergooner accomplishes this in a basic no-frills manual mode. In Summer time, pop the hood and turn off the flow, and when it gets cooler outside, pop the hood and open the ball valve. The thread on the other form has ~100 replies with various stories, approaches, measurements and suggestions on this mod. The consensus is that for <$20 in parts and 30' under the hood you get an instant 10 degrees cooling in the cab. I hope this helps.

 

1-bigmac, do you happen to have a link to some of the pics/info on this.
I might very well do this, being that it's already 95 degrees w/90% humidity in my parts.

 

Well I dont have temp differences, but my dual electric fans has helped with in town cooling.

 

Here's a link to Spoonergooner's ball valve mod:
I fixed my poor A/C performance - Page 2 - F150online Forums

 

Alright folks, here's your general rule of thumb when it comes to a/c in a vehicle, any vehicle, it's all dependent upon ambient temperature, your a/c should cool down 30 degrees below the outside air temprature and that's w/ the max setting on and the vehicle sitting still. Some may get colder. Since the a/c in any vehicle is also dependent upon a properly working cooling system, it will get colder as you drive down the road when air is forced across the condensor coils and the compressor is pumping faster. So if it's 100 degrees outside it would be normal for the a/c to be blowing out 70 degree air while sitting still, though as I said before, SOME WILL GET COLDER. This is not speculation or myth but absolute fact. To the OP, it sounds like your compressor is cycling a little too fast, usually an indication of an improper charge of 134 or freon. you could definitly get it to blow 10 degrees colder than it does now.

 

Yeah, you guys do get pretty bad humidity down there Matt

 

here is a link to the ball valve you need from Lowes:
3/4" Ball Valve PEX Ends