compressor kicks in but no cold air..
06-11-2011, 03:30 PM
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compressor kicks in but no cold air..
hi there, i need help figuring out whats the deal with my 87 pickups AC....Well two years ago it worked fine, then it faded out, i figured i ran out of 134a (its been converted) well this year i decided to fight the texas heat so i went to this guy who vacuumed the system and put new 134a in there. Well the light comes on the dash, clutch kicks in, rpms go up at idle but i get no cooling AT ALL.....I can turn the compressor by hand and turns fine with little restriction.... Im lost... any help would be appreciated.!
06-12-2011, 12:39 AM
#2
Are you sure the compressor is pulling in??
If it is take it back to who pulled the vacuum if they were able to hold a vacuum it in theory should not have a huge leak.
Are all the cables that work the different flaps and turn the heater valve off working like they should??
Do you get any flow of air out of the dash vents mouse nest ???
If it is charged if the compressor clutch is pulling in it should work
If at the time of charging if something was Fubar it would show up in the pressures not being what they should.
One of those things hook the gauges up and see what you have.
If it is take it back to who pulled the vacuum if they were able to hold a vacuum it in theory should not have a huge leak.
Are all the cables that work the different flaps and turn the heater valve off working like they should??
Do you get any flow of air out of the dash vents mouse nest ???
If it is charged if the compressor clutch is pulling in it should work
If at the time of charging if something was Fubar it would show up in the pressures not being what they should.
One of those things hook the gauges up and see what you have.
06-12-2011, 04:09 PM
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thanks for the quick reply, one thing i do not know about cars is ac...unfortunately. Well the compressor does kick in for sure, at least the magnetic clutch does accurately with the press of the button... and yes all cables work well, i can switch to all options, expect the number 1 speed on the fan blower, which i think is weird. Anyhow, when the guy put new refrigerant, the system had a quite a bit of air..... he vacuumed and put new can. this was almost a week ago, and the clutch still engages, which tells me that there is refrigerant on the lines, because if not it would not kick in. That tell me i think that i have no leak.....or a small one so far...
i also noticed that the line that goes from the compressor to the condenser, gets REALLY hot, and the other one not much at all, just by having ac on but a minute or so at idle... i also checked the fuse behind glove box=good.. thanks again
i also noticed that the line that goes from the compressor to the condenser, gets REALLY hot, and the other one not much at all, just by having ac on but a minute or so at idle... i also checked the fuse behind glove box=good.. thanks again
06-12-2011, 04:11 PM
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unfortunately i have no access to gages, and when the dude did it, a had no clues what they mean, should have asked. but the needle was all the way arround when full i guess
06-12-2011, 05:14 PM
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go to harbor freight and buy yourself a set of those crappy gauges... you'll need to know what the pressures are, otherwise you're just taking crack shots at this
there's many things that can cause no cooling... lack of airflow, too much/little freon, line restrictions, bad compressor, bad expansion valve/orifice tube, etc
there's many things that can cause no cooling... lack of airflow, too much/little freon, line restrictions, bad compressor, bad expansion valve/orifice tube, etc
06-12-2011, 05:49 PM
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Sounds like a restiction in the system. The discharge line does warm up due to the refrigerant compressing. The condensor could be plugged or the orifice tube. There should be a temp differrential before and after the orifice tube. Warm inlet, cold outlet. Guages will show where the restriction is.
Does the compressor cycle or just stay engaged? Hard to diagnos a/c systems in the driveway because you need ram air across the condensor.
Take it back to uour guy and have him read the guages to find the problem
Does the compressor cycle or just stay engaged? Hard to diagnos a/c systems in the driveway because you need ram air across the condensor.
Take it back to uour guy and have him read the guages to find the problem
06-12-2011, 06:32 PM
#7
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there's no orifice tube in these trucks... not any toyota I heard of... they have expansion valves 
while they both serve the same purpose, they work very differently
you can do most diagnosis with the vehicle stationary... only seldomly do you need to road test, otherwise you'd see every mechanic and A/C shop road testing cars for any A/C problems! the "ram air" is provided by the radiator fan
while they both serve the same purpose, they work very differently
you can do most diagnosis with the vehicle stationary... only seldomly do you need to road test, otherwise you'd see every mechanic and A/C shop road testing cars for any A/C problems! the "ram air" is provided by the radiator fan
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06-12-2011, 06:50 PM
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Expansion valve, your correct. Sight glass and so on. Forced air is used to simulate road driving. A/C shops use this method. And yes, why wouldn't you road test an a/c service or repair ? You pay for it in the invoice. 
06-12-2011, 06:55 PM
#9
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I'm saying, initial diagnosis typically do not involve road test, only does final check after repair does
the radiator fan is supposed to do it's job while the car is at idle, and if it's not, we'll have millions of angry motorists complaining their A/C don't work in rush hour during the dog days of summer!
the radiator fan is supposed to do it's job while the car is at idle, and if it's not, we'll have millions of angry motorists complaining their A/C don't work in rush hour during the dog days of summer!
06-12-2011, 07:08 PM
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does it cycle quickly? if yes, you are low on 134a.
don't get the harbor freight gauges. i just bought a set for 50 bucks. 2 reasons not to. #1) The gauges are in Celsius, not Fahrenheit. 2) They do not come with a means to charge via a small 134a can that you find in wally world. (you can use a 20 lb tank if you do this for a living) you need to buy a $20 adapter that has the screw on needle thingy for charging with cans.
Carquest has a set for $55 that is in Fahrenheit and comes with the adapter for the small cans.
don't get the harbor freight gauges. i just bought a set for 50 bucks. 2 reasons not to. #1) The gauges are in Celsius, not Fahrenheit. 2) They do not come with a means to charge via a small 134a can that you find in wally world. (you can use a 20 lb tank if you do this for a living) you need to buy a $20 adapter that has the screw on needle thingy for charging with cans.
Carquest has a set for $55 that is in Fahrenheit and comes with the adapter for the small cans.
06-12-2011, 07:34 PM
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what does it matter if it's celsius or fahrenheit as long as the gauges read in PSI? the low side gauge always equate approximately to the fahrenheit temperature scale... this is one reason why it was difficult replacing R12 because R12's pressure scale was a direct equivalent to the temperatures... R134a took a while to come out because not only of the engineering requirements in a motor vehicle, but also the desire to keep things simple like R12
06-13-2011, 02:58 PM
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well yeah i heard cheap gages are no good.... anyways, i talked with a guy today and he mention to check gage pressures, and he mention ideally outlet should be at around 300 psi, and inlet at around 50 psi. does this sound correct? well ill have to go find gages and Ill post the results.
06-13-2011, 03:01 PM
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does anyone know how to get to the expansion valve? i know is somewhere in the dash but does not look like fun to reach in there....
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06-13-2011, 03:28 PM
#17
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I haven't worked on these mini trucks enough so I don't know
but you might be able to get to it by taking the glove box out, then pulling the evaporator unit out... it is attached to the evaporator core and you can't really get to it without taking it off
but you might be able to get to it by taking the glove box out, then pulling the evaporator unit out... it is attached to the evaporator core and you can't really get to it without taking it off
06-13-2011, 05:07 PM
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To get the compressor to work long enough to take the freon you sometimes need to jump the low presser switch . If the jumper is left in it will let the compressor run with out freon. It is a safety device. I do not know off hand where the switch is located on your truck. Maybe someone can help with the location.
06-14-2011, 08:44 AM
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well here is the thing...i when back to this guy to check pressures and i only had about 90psi on the outlet...means i had tons of air....mostly a leak.... it has been about a week since the vacuum and one can of freon. The guy suggested for me to go to autozone and get 2 cans and a stop leak and he'll help me out by vacuuming again and putting all that crap in ... do you all think it will work? At the moment, there absolutelly nothing on the system anymore= compressor will not kick in anymore.
