I need some AC help...

Been fighting it for about a year now and I am sick of it. I have a few hundred to fix it, but before I take it somewhere maybe one of you can help me guess where it is.

Right now the AC barely works, to keep the cab tollerable in 100* heat it has to be on MAX and FULL blast.

Right now I have both pressure sensors bypassed with jumper wires, if I plug them in the AC pump does not come on. I have used those cheap refill things from wal-mart with no improvement.

I thought it was an issue with the wire harness so I got a new one. NOPE

So I am thinking it has low pressure, and maybe a bad pressure sensor.

Or can they have too much pressure and not work good? I figured if it had too much pressure it would blow cold, but as a safety the switch would open so you would get it fixed?

Hot in Santa Fe... LOL

Is your compressor worth a crap? Unless its that a/c fixes are usually pretty cheap in my experiences to just let a shop mess with it. but if you have a way to rule out the compressor that all i got.

Well the compressor runs, I know that much. Truck has 200k on it, so I guess the compressor could be getting old, but most of the time I dont need AC.

I'm over messing with it myself! LOL

Mine was doing some bs like that Joe and I took it to ma n pa type mechanic and he had to evacuate the system and recharge it because there was some moisture that got in the system and the chit froze in there, plugging orifices. Worked great for two years and then last year my windshield started leaking and my gem is caput so mine blows out the defroster only.

Its been in the high nineties here and I need mine fixed too. Yours could be the compressor though too. Does it stop blowing intermittently and you'll get hot air for second?

Joe is it blowing any cold air at all.? How much gap do you have on your compressor clutch ? Is it engaging ?

Edit - sorry I didn't see post #3

Take it to the shop then! Let us know what happens. A/c systems suck for messing with. Over my head anyway.

could be moisture as stated eairler. Also if you have too much in the system could also cause problems. Gotta let the liquid turn to vapor then back again in order to work. If ya got pressure, compressor should be ok. did you compare the high side and low side? Most ac systems will cool the cab 20 to 30 below outside air temp. 30 is really good.

CSIPSD said:

Right now I have both pressure sensors bypassed with jumper wires, if I plug them in the AC pump does not come on. I have used those cheap refill things from wal-mart with no improvement.


Or can they have too much pressure and not work good? I figured if it had too much pressure it would blow cold, but as a safety the switch would open so you would get it fixed?

Hot in Santa Fe... LOL

Click to expand...

Dear Hot..
Yes, the system can be overcharged to the point it does not cool well.



I'm thinking it's overcharged to the point it's locked out electrically. I get a lot of those in the spring.. like someone else said, refrigerant traps moisture. It's supposed to be filtered out by a desiccant in the accumulator, but it can become waterlogged. Guys will throw Wal-Mart hand grenades at it, and over charge it.

Do you have any access at all to a gauge set?

LOL, you just asked if Joe had access to guages. LOL.

Probably mounted in the glove box.

need pressures to tell the story...

Arisley said:

LOL, you just asked if Joe had access to guages. LOL.

Probably mounted in the glove box.

Click to expand...

If not already, Im sure he has a hook up to get some.LOL

Arisley said:

LOL, you just asked if Joe had access to guages. LOL.

Probably mounted in the glove box.

Click to expand...

that was a pretty stOoPiD thing to ask the gauge whore, wasn't it...
I just wned: myself

part of your issue is the two sensors you have bypassed. the system works kina like this. your compressor compresses the freon onto a rediculously small orifice. it travels through that and then "flashes" (think rapid expansion from tiny orifice to large tube) out into a larger tube. when it flashes is when it gets cold. when the pressure goes from super tight orifice to less pressure in the larger tube.

there are two sensors. one is a low pressure clutch cycle switch and a high pressure switch. both of those are needed to maintain very specific pressures inside the system. to much pressure your ac gets hot, not enough pressure your ac gets hot.

when you add freon to a system, you need guages and some sort of a monitering device to determine how much is in there, and how much you put in. to do it your self, you need more guages. if you over charge it you will lose some cooling, under charged, obviously you lose cooling. my truck, E99, used 2 lbs of freon. thats what the book called for.

you can go to a ac shop, and they can recover the freon you have in it, then evacuate the system, then put the freon back into it, +/- to make it right. we had to evacuate my truck twice before we got it all out. thats normal. sometimes it takes once or twice to get it all out.

the orifices i was talking about earlier is what freezes. when your driving down the road a bit, and your ac on full blast, pull over. by the blower motor, is some silver tubes for the ac. look at them and see if there is frost on them. if there is, that is one orifice that usually freezes. if you have "outside air" inside your system it freezes the moisture in it and it cannot pass through the orifices, thus blocking the system. that orifice costs approximately $1. yes, that cheap. but you have to open the system to get to it, pull it out, looks like a pencil kinda, and put back together, and recharge. it is a pita to get that orifice out.

200k on your truck, the air gap might me a little loose. take the pulley off the front of the compressor, and take approx 15-20 thousandths of shim OUT, and put back together.

i am not a ac guy. im a tree trimmer. but i just got done talking to a shop couple days ago about why my ac is not as cold as it used to be, and those are the cliff notes of a 45 min conversation. hope they help.

I think I am going to take it to a shop today if I have time. Contract completion today and I still have to finish paving the parking lot... fubar.

LOL... No AC gauges, but I did see them at AutoZone yesterday.

CSIPSD said:

LOL... No AC gauges, but I did see them at AutoZone yesterday.

Click to expand...

and you were tempted to get them, weren't you?

what was the outcome of this little adventure?

JLDickmon said:

and you were tempted to get them, weren't you?

what was the outcome of this little adventure?

Click to expand...

tempted? he probably bought two sets...

JLDickmon said:

and you were tempted to get them, weren't you?

what was the outcome of this little adventure?

Click to expand...

LOL... No, they were not Isspro.:bs:

I have not had time to go get it looked at. Going to Pepboys tomorrow, they do a free AC check, so I will start there.

Tree Trimmer said:

tempted? he probably bought two sets...

Click to expand...

LOL...

CSIPSD said:

LOL... No, they were not Isspro.:bs:

I have not had time to go get it looked at. Going to Pepboys tomorrow, they do a free AC check, so I will start there.

Click to expand...

Lemme know what they say?

Ask them what the gauge readings were at both idle, and at 1500 rpms.

Believe the low pressure switch is the problem... I ordered both and will install tomorrow.

Once that is done I will go back and have them check the pressures.