I need some AC help...

moose99psd · Jul 28, 2011

ummm to change those switches you have to open the system i believe witch means an evac and recharge...

97spoolinstroker · Jul 28, 2011

do you have any way to put gauges on it to test the pressure maybe have a leak some were because if those systems get low the compressor wont kick on and that why your not seein it spinning at the belt

CSIPSD · Jul 29, 2011

moose99psd said:
ummm to change those switches you have to open the system i believe witch means an evac and recharge...

I have been told there are shrader valves behind those switches... We will see tomorrow afternoon

97spoolinstroker said:
do you have any way to put gauges on it to test the pressure maybe have a leak some were because if those systems get low the compressor wont kick on and that why your not seein it spinning at the belt

They checked the pressure, and there is pressure in there. If I bypass the switches with jumper wires it blows cold, just not as cold as it should.

Tree Trimmer · Jul 29, 2011

the low pressure switch is about a $15 part, that does not require a evac of the system to put on. i put one on my truck a month ago. simply unscrew old one and put new one on. i cannot say about the hp one though. didnt need one of them.

mine was, drive down the road and the ac would get cold then warm, then cold then warm. replace the lp switch, fixed. i was told the hp switch was like $130, though we didnt look it up, i just told him to guess as i was curious, be interested what you pay for it

JLDickmon · Jul 29, 2011

CSIPSD said:
I have been told there are shrader valves behind those switches... We will see tomorrow afternoon

there is

CSIPSD said:
They checked the pressure, and there is pressure in there. If I bypass the switches with jumper wires it blows cold, just not as cold as it should.

might be a titch wet..
if pressures are OK and it still doesn't blow as cold as it should,
you're probably looking at an evac/recharge..
depending on the year of the truck and the last time the system was opened, I might tell you to change the accumulator as well..

02BigD · Jul 29, 2011

I had the issue that the compressor was cycling on/off. Wouldn't blow even cool at idle, only worked correctly at 2000 RPM's.

Ended up being too much freon. Works normal again now.

CSIPSD · Jul 29, 2011

Tree Trimmer said:
the low pressure switch is about a $15 part, that does not require a evac of the system to put on. i put one on my truck a month ago. simply unscrew old one and put new one on. i cannot say about the hp one though. didnt need one of them.

mine was, drive down the road and the ac would get cold then warm, then cold then warm. replace the lp switch, fixed. i was told the hp switch was like $130, though we didnt look it up, i just told him to guess as i was curious, be interested what you pay for it

Yup, $18 bucks for the low pressure one and $23 for the high pressure... Not 100% sure we ordered the right high pressure one, but it was for all years 1994 to 2005!

CSIPSD · Jul 29, 2011

Well... New low pressure switch and the AC is blowing 45-50* when its 95* out. Not bad, still not as cold as I remember it once being.

I will buy the pressure gauges myself maybe next week and check the pressures.

Just a little PISSSSS of Freon when I removed it.

One thing to note, I got a 2002 wire harness to replace mine a year ago or so, something changed in the wires between 2001 and 2002... It will not work. Swapped back to my old one, and it took right off.

Arisley · Jul 30, 2011

CSIPSD said:
Well... New low pressure switch and the AC is blowing 45-50* when its 95* out. Not bad, still not as cold as I remember it once being.

I will buy the pressure gauges myself maybe next week and check the pressures.

Just a little PISSSSS of Freon when I removed it.

One thing to note, I got a 2002 wire harness to replace mine a year ago or so, something changed in the wires between 2001 and 2002... It will not work. Swapped back to my old one, and it took right off.

Didn't they eliminate one of the fuse panels in 2002? With that major of a change, I bet a lot of other changes happenned at the same time.

Southmike · Jul 30, 2011

So how do you change out the lp switch, i may have to look closer at mine as i just have a simple guage.

CSIPSD · Jul 30, 2011

A wrench.... LOL

Remove and replace.

06f3506.0 · Jul 30, 2011

I had similar problem with my truck it was the compressor went bad. I talked to a guy that does ac on vechials and he said ford actually had a problem with them. I put a compressor in and cleaned out lines as good as possible re-charged and it works good. Tried to find info on it but nothing came up. Ford has a whole right up on it

Tree Trimmer · Jul 30, 2011

mike, the one im pointing at is the hp switch, and the shiny one is the new lp switch. simply unplug, unscrew, screw, replug, done.

jwlandry · Jul 31, 2011

Fwiw mine will cool down to 38-40 and it's good on pressure and freon. So with you at 40 it's pretty close.

Arisley · Aug 1, 2011

I thought you would lose all the freon of you pulled those switches out. Good to know.

CSIPSD · Aug 1, 2011

Nope, there is a valve behind them... Just a little bit.

I think I am going to go get the gauges and check the pressures... There only $50 bucks so...

Tree Trimmer · Aug 1, 2011

Arisley said:
I thought you would lose all the freon of you pulled those switches out. Good to know.

nope, just a dribble, and a quick pssst.

SkySki Jason · Aug 3, 2011

I STRONGLY recommend switching to a (part #) 38639 orifice tube if you open the system up for any reason. This part costs less than a cup of coffee and can lower your AC vent temps by 10*. My PSD's both have this now and will comfortably blow air 40* plus below ambient temp. Sitting in the X as we speak, been idling at 1100rpms in 100*+ for over an hour and my center vent temp is 59*. On the road I can see 50* vent temps in this weather!!! :redspotdance:

One of the most common issues with AC systems that 'used to blow colder' is blocked condensors. It doesn't take a whole lot of bugs, mud and bent fins to dramatically reduce the efficiency of the condensor. I've never used 'condensor cleaner', but I guess this type of product is just for this task and probably is safe for aluminum and any coating that may be on it??? Either way, remove the grill and get that sucker as clean as possible!!!

The high-side switch has been by-passed on my F350 for years, no issues with COLD ac in even the hottest weather we get in the USA. I agree that too high pressure will reduce cooling, but my experience is the compressor stays on all the time even with the switch - my assumption is this is for safety in the event there was some blockage or something so over-pressure didn't break something.

CSIPSD · Aug 3, 2011

Well I have a newer condensor (about 4 years ago) and its protected behind my gril and screen so its in good shape more or less. I will change out the orifice if I have to open it up. Honestly I am thinking about getting a few books and playing with this stuff a bit.

The AC in Chelseas Excursion does not blow as cold as I would like, but its colder then mine.

How does this sound...

92* yesterday and I was getting 45* out of the vents when moving?

Could it be an issue with the Fan not pushing air as hard as it used to? I remember my OBS would freeze you out of the cab, this one just doesnt do that.