AC Issues

[SmokeShow]

I know next to nothing about the AC system on our trucks. What I do know is it's hotter than blue blazes out & mines not working & it did last year. LOL

I bought a recharge kit & recharged the system per the instructions on the bottle. The system holds the pressure that the recharge kit says it should.

I think something is wrong with the compressor. It kicks on for a sec then cuts back off. Is that characteristic of a bad compressor or maybe a bad clutch on it? It seemed to only kick on for it's short spin while I was giving it a hit of coolant from the can. When it would kick back off, it would snort a mist out the front of the compressor wheel.



Any ideas?

 

[x MadMAX DIESEL]

Did you let turn the ac on for a bit before you charged it?

 

[maxaholic]

What does the pressure read? If there is not enough freon in the system it will kick the compressor on and off.

 

[Burn Down]

You shouldn't get anything out from the pulley area of the compressor. Sounds like the seals are out. Before you junk it though, take it into a shop that does a/c and have them pull a vacuum on the system, it should hold that all day long, if it won't hold a vacuum you have a leak. If the R-134a is low the low pressure switch will keep the compressor from engaging and burning its self up

 

[SmokeShow]

the recharge kit I bought has a gauge on the hose between the refill canister and the port on the AC tubing... before the first fill, it was below 35. The directions on the can said to fill it to 35psi so I did. It still didn't work so I ran for a while longer (only drive truck when I'm home on the weekends) then charged it some more yesterday to about 42 psi which is in the middle of the caution area on the refill canister.


Sounds like this is an issue I'm not even going to be able to diagnose. Guess I'll take it to some place if I get a chance.


Thanks guys :beer

 

[maxaholic]

You shouldn't get anything out from the pulley area of the compressor. Sounds like the seals are out. Before you junk it though, take it into a shop that does a/c and have them pull a vacuum on the system, it should hold that all day long, if it won't hold a vacuum you have a leak. If the R-134a is low the low pressure switch will keep the compressor from engaging and burning its self up

I need to read better. I totally missed that part.

 

[THEFERMANATOR]

the recharge kit I bought has a gauge on the hose between the refill canister and the port on the AC tubing... before the first fill, it was below 35. The directions on the can said to fill it to 35psi so I did. It still didn't work so I ran for a while longer (only drive truck when I'm home on the weekends) then charged it some more yesterday to about 42 psi which is in the middle of the caution area on the refill canister.


Sounds like this is an issue I'm not even going to be able to diagnose. Guess I'll take it to some place if I get a chance.


Thanks guys :beer

You are reading that pressure with the A/C on max and inside air correct? At 20-22 PSI the low pressure clutch cycling switch will disengage the compressor. You ALWAYS charge an A/C with it running at full bore. Depending upon inside and outside air temps it will vary the low side pressure GREATLY. The easy cheater way to do it safely is to park the truck in the shade(if possible), turn the blower on high, turn the A/C on, set it to inside air, begin charging the system to about 40 on the low side until the compressor begins to stay on while charging. Next observe the low side line going intro the compressor(the bigger line that hooks to it). You want to charge the A/C until this line is getting cold right at the compressor. Don't go beyond this point and you will be safe.

 

[SmokeShow]

yes, I did have the AC on inside and fan on high. Maybe it just needs more? Am I understanding correctly that I need to keep charging until the compressor stays on while charging? It is already at 42psi on the gauge of the recharge line which I'm assuming is the low pressure side. The charge kit only lets you hook the line up to one of (the correct one) ports.

Maybe it just needs more?

 

[THEFERMANATOR]

Could be a bad guage, or a bad low pressure switch. Does the guage move when the compressor kicks on and off? It coul be just a very slow moving guage that can't keep up with the pressure changes in the A/C system. Orr you could have a plugged orifice tube and the high side switch is kicking it off due to 350 on the high side. The pressure should be right around 80-95 with the A/C off and the compressor not running and the system has had a chance to sit and normalize. Do you happen to know what it is at before you turn the A/C on?

 

[sweetdiesel]

Just throwing this out there but if u run a different op systym than ur truck is it can make your ac not work

 

[x MadMAX DIESEL]

Just throwing this out there but if u run a different op systym than ur truck is it can make your ac not work

Just throwing this out there but I don't think Mitch has changed tuning on the truck for awhile. Good thought but I don't think thats the case here

 

[SmokeShow]

Correct, tuning hasn't changed. If it were tuning, what part of the system stops working properly?


With the gauge hooked up, not charging & compressor not running, that is when the pressure is 42psi. While charging & the compressor kicks on, the pressure goes to 90ish. The compressor doesn't stay on for more than a couple seconds when it does kick on. I don't recall it kicking on unless I was charging. It Only kicked on one or two times for a second when I wasn't charging. I didn't notice a change in pressure when it kicked on without charging. I also never felt the pipe to see if it was getting cold. I did touch the canisters on top of the compressor & both were real hot to the touch. Lol

 

[madmatt]

let truck sit in shade with a/c off for 10-15 minutes, put real gauges on (not whats on the can) and check static pressure first. Get number, report back

 

[Chevy1925]

Correct, tuning hasn't changed. If it were tuning, what part of the system stops working properly?


With the gauge hooked up, not charging & compressor not running, that is when the pressure is 42psi. While charging & the compressor kicks on, the pressure goes to 90ish. The compressor doesn't stay on for more than a couple seconds when it does kick on. I don't recall it kicking on unless I was charging. It Only kicked on one or two times for a second when I wasn't charging. I didn't notice a change in pressure when it kicked on without charging. I also never felt the pipe to see if it was getting cold. I did touch the canisters on top of the compressor & both were real hot to the touch. Lol

sounds like your got some bad things goin on. First, your gunna need a gauge to read the high side pressure as well as only readint he low side will tell you half the story, not all of it. I also know that on the 01-02s they had issues with the orfice tubes plugging themselves up but it seems more like your compressor is going if you have had no probs with it this far. Very rarely do the pressure switches go bad but they can leak. Personally id say you need to take her into someone you trust. hell if you were closer id hook my gauges up for ya and we could get her figured out. It really sounds like a big restriction somewhere and 90% of the time the restrictions comes from a compressor coming apart (could also be a hose falling apart interanlly or something else but gerneally thats not the case) . Is one of these love/hate relationship for the mechanic and the vehicle owner.

 

[Burn Down]

I know next to nothing about the AC system on our trucks. What I do know is it's hotter than blue blazes out & mines not working & it did last year. LOL

I bought a recharge kit & recharged the system per the instructions on the bottle. The system holds the pressure that the recharge kit says it should.

I think something is wrong with the compressor. It kicks on for a sec then cuts back off. Is that characteristic of a bad compressor or maybe a bad clutch on it? It seemed to only kick on for it's short spin while I was giving it a hit of coolant from the can. When it would kick back off, it would snort a mist out the front of the compressor wheel.


Any ideas?

It should never leak here, seals are bad on the compressor.

 

[THEFERMANATOR]

What color is the snort you get out the front of the compressor when it kicks off? If it is dark then chances are it's just dust accumulated behind the clutch. If it's a whitish cloud then it's refrigerant. 42 just sitting there isn't enough to turn the low pressure switch on(needs at least 50-55 for it to re-enage the switch). Real guages are defiantely you're friend here as you need to see what the pressures actually are. Those cheapos are are just a throw away basically and are inaccurate at best. The 90 while charging sounds normal as R-124 goes from liquid to gas at roughly 85-90 pounds of pressure on a 85-90 degree day. That is why most A/C systems will have 85-95 pounds of pressure in them when equalized as that is the vapor pressure point of R-134 at the average summer temp.

 

[REDHOSS02]

i was having a similar problem with my a/c but my pressures were good high and low but the compressor wouldnt engage. checked all the pressure switches(good) so i pulled the relay and swapped with another...still nothing....so i jumped the relay and walla i have a/c how it worked i have no clue and didnt waste time trying to figure it out. I left the relay out and found an on/off switch in my garage and ran a wire through the firewall into the cab and i cycle the compressor myself. I know this isnt right but its all i can do for now! it works!

 

[jmaz268]

^^^^what he said..

 

[jmaz268]

disregard....beat me to it lol