I would think that having a system that cycles the compressor on and off is just overkill. The compressor would have to cycle way too many times. Have you guys ever been driving down the freeway with either a/c or max a/c on, (nice and cool) then switch to vent (shutting down compressor). It doesn't take more then a few seconds to feel the difference in temperature coming out of the vents. As a matter of fact you need to switch to a/c again quite quickly or it becomes uncomfortable. So for this reason i believe most automobile a/c systems use the blend door to control cab temperature. I personally have not owned a vehicle that i have been able to notice cycle the a/c compressor on and off to control cab temperature.

I am not sure those premium A/C systems actually cycle the compressor. We used to own a lincoln continetal with one of those systems and as far as i can remember i can't recall the compressor ever cycling. I think they just have a ($$$$$) way of blending the air to meet a desired temperature.

By the way, the a/c in that continental was a pain in the butt. Always had problems with it. Actually let me take that back.... The whole car was a pain in the A$$. absolute junk.......

 

Here you go Bob, bump.

 

Update guys. I found an electric 12" fan that I had installed in my old Grand Marquis. I wasnt doing anything, so if figured what the hell.

I installed it on my truck, and god dang. Its powered with the blower motor and man it dropped the temp a couple of degrees. That really helps in the 100 degree heat!

 

The best advantage I found on this mod is the ability to use the vent. Even in 60 degree weather I could not use my vent when towing, the air coming out was just too hot. Now I enjoy the cool vent in cooler weather.

 

Yes, but that's when you tap into the red vacuum line. I like using my heat on that setting too much to go that route. I'm used to my Ranger working the same way, so it's a no-brainer for me. Here in North Texas, you can only use the vent without AC or heat about twice a year for a week or two each. Seems like it's either cold & wet or hot & dry here. Although this year it's a really wet summer, so the compressor is required anyway because of the humidity.

Joe

 

I did this today, I now have a rolling freezer. On max A/C rolling about 65 mph, my outlet temp was 42*,

 

Did you happen to check it before you installed the mod?? I'm about to undo the vacuum and check it both ways...

Joe

 

Here's what happened to my mod over month ago:

"Results:
1. I measured the coolest point in Max A/C before this mod:
Outside temp: 94F
During 10min driving , the coldest the A/C got was 50F , measured from the mid vent with fan speed II.

2. After mod was in:
Outside temp the same 94F
The coldest through A/C Max, 42F , measured from the same point, fan speed and same driving time. It is almost OK beer temp?

So 8F degree drop . But it felt much cooler than what the thermometer showed. You can catch cold with this thing now.

What I did not measure, was the time how fast it got the coldest temp. I'm pretty sure it gets cooler faster too."

This is one of the best mod's so far. Today was 104*F and it gets still cool enough that you had to drop it once a while from Max to A/C and with the lowest fan speed.

 

Well I have read thru this entire thread and want to thank everyone for some very usefull information. But I am still a little confused I live in SouthWest AZ and it gets hotter than He!! out here in the summer (it's already reaching the 110's down here). I plan on ordering the DS kit for my '03 F250 but I am not sure it will work for the Wifes '02 EX (and this is the vehicle that I really needs it) The A/C blows reasonable cool while moving but at idle it just plain sucks!! It's got the dual A/C unit with the electronic controls on the dash. I haven't read if these types of systems would benifit from this mod or not. I was thinking about just buying the $2 manual shut off valve for now just to see if it will work. Then if the results are favorable ordering a DS kit.
What do you guys think? And if I was to try the $2 valve What size and where would I find something like that?
Thanks again guys,

JB

 

While reading through all of this thread, you should have come across the information that EX's already come from the factory with these valves installed.

That means, in essence, that Ford already did this "mod" for you.

I wouldn't put another one in, if I were you...

Pop

 

Hey pop, I did read the threads about but I guess I must have misread somewhere I thought it was after 2002 that Ford did this "mod" or they didn't do it to all the models. I will have to go back and re-read the thread.
What would I be looking for under the hood to see if this has already been done.

Thanks for the reply,

JB

 

I thought I read that it still doesn't cut the coolant all the way off like the Ranger and the DS valve. Check it by setting your AC to Max and run the temp **** up to warm and see if it warms up. Mine is still ice cold even with the temp **** all the way to the right, meaning zero coolant flowing through the core. Obviously, do this after the engine has warmed up...

Joe

 

cptSD

I live in the imperial valley, so the climate here is very similar to yours. I decided to go with a manual shut off valve from Napa.

I don't remember the last time i had to use the heater in the morning and the a/c towards the evening. Here it is either very hot or not. So i figured a manual would not be a problem for me.

i just asked for a heater shut off valve at napa, i believe it was a 5/8 in.

 

A/C while idling! As most of you know the A/C doesnt work well while at idle, the reason is there is not sufficiant air flow across the A/C condensor, once you get out on the road the A/C gets COLD. The way to fix this problem is one of 2 ways.
1. Replace your existing clutch fan with twin electric fans, This is a bit costly, the average cost is generally around $500. These are nice set ups, complete with shroud and thermostat controls. This will move air across you A/C condensor at a much greater rate thus this temperature drop means colder A/C while at idle. Be carefull, you need a set of fans that are rated (CFM) for our trucks and the load you are hauling. I made my own set up with some 18 gage sheet metal, a couple of high CFM fans and a set of controls for around $150,
2. Get a 12-16" fan and mount it on the front of your A/C condesor, You can use a manual switch or other means to energize it, while you are at idle or slow moving trafic turn it on, I droped my temp 15* while idling by doing this.

I also did the ford ranger mod, this weekend and that helped even more, my average output while on the road at 65, fan on med was 42*.

 

Hey UcaN, I'm over in Yuma so our climates are just about Identical. I believe the manual shut off valve will work.

Thanks for the info.

JB