throttle controlled a/c???
 

on my brothers 99ford f250 his a/c blowers weaker the harder your on the gas

is that the a/c clutch or a vacumm leak or what??

I don't know much about A/C (nothing really) but I think older cars had a vaccum ball valve that has something to do with the airflow on acceleration...something like that

Probably a vacuum leak, and as Tod said, there's a reservoir somewhere. I think it's on the rh fenderwell. There's a lot of hard plastic vacuum lines on that vintage Ford, so it may take a while to find. Good luck!
Johnny

does it switch from vents to defrost ehen this happens if it does look for white plastic vac line on pass side fender near firewall will be cracked

Some models used a vacuum switch to cut the compressor off under hard acceleration (high vacuum). Another way to assist the net HP numbers Detroit threw at us.

Dave

I have 2x55 AC, 2 windows down 55 mph. 8)

hey blow injector you better be goin more than 55 with that big ol' blower haha but we just recently had some work done to the vacumm resevoir cause it fell off and he ran it over and after that the air only blew out the floor vents but now it has the new throttle control problem.

Ok first, Does the blower motor slow down or does the air stop cooling? Vacum has nothing to do with the blower motor, it is 12 volt :!: :!: If the air flow stop's there is a plug on the drivers side of the heater box, it connect's the engine vacum to the box, it has a Red, Yellow,Green, Black vacum lines, Ford had a problem with these connectors leaking. The vacum line going thru the firewall to box should branch off of the brake booster, if the booster is leaking vacum, it will starve the box blend door,floor,defrost,panel, accurator's when you get on the fuel.... HOPE THIS HELP'S :!: :!:


''JUST MY TWO CENT'S WORTH''

The thing I was talking about didn't have anything to do with the blower motor it was my understanding it had to do with the flaps/ductwork. But that was on a 72 chevelle.Sounds like MOPAR68 knows what he is talking about I'd check that.

well mopars advice hasnt lead me astray yet so ill check that tomorow

gusse thats the kind of knowledge you get workin at a dealership hu mopar

and thanks im tired of havin to let off the gas to get a break from this triple digit weather were having down here

mopar,
do the fords have a 1 way check valve in the vacuum line like the dodges did in the 90's? that was a notorious problem back then, the valve would go bad and when you accelerated the system would lose vacuum. those valves are about $4 if I recall...

Well maybe you can fix the Ford and my Chevy 2005 2500hd. Sometimes when you crank it up the ac blows hot. I don't care how long it sits or how much you rev it up it blows hot until you start to drive. When you start driving it turns cool in just a few seconds. Always blows cold once it starts. Chevy replaced the accuator valve and it worked normal last summer, but has started doing this again.

check the plug that is rite where passengers foot is on the hump, I have had passengers kick mine lose and caused mine to do the same.(dumb place for wires)

Yes Chris they sure do :!: :!:


''JUST MY TWO CENT'S WORTH''

I would have to say that the AC is bypassing at high RPMs it builds to much head pressure and doesn't work effectively. Same thing happens if your seating still to long. Only diff is head pressure is high because of heat not RPMs....

Cooling fan keeps head pressure down, that is why cooling fan mostly works during stop & go traffic, not at highway speeds, wind keeps it cool.


''JUST MY TWO CENT'S WORTH''

I agree Mopar1968 but if you stop at a light for very long time on a real hot day the fans won't keep up completely, that's why the air will start to blow warmer. Especially now with 134 A since it expands so much more with heat than the old R12 did...