I have an 87 mustang GT w/a 5.0 The air blows in the car but it isn't blowing cold so i figured i'd buy a charge kit and give it a boost, well i purchased the kind with a gauge and before even filling at all it indicated that i was at 100psi and in the red zone already where the safe level was around 45 psi. i was wondering if there was a way to bleed the system so i could try adding fresh coolant or is there somthing else maybe wrong. I'm fairly sure i can hear the compressor kicking on and off every few minutes...it's 90 degrees here everyday and I'm getting sick of a hot car seeing as my convertible top will be out of service for another few weeks
you gonna see 2 black cap.one for low pressure and the other one is hight pressure.open those cap's and releif pressure from your a/c line.after that your system gonna be purge.you will abnle to put around 2 1/4 pounds of coolant stuff.
A few things...
1) Make sure that you can see your compressor spinning.
2) Make sure you are filling it at the correct pressure port. If you use the wrong one, you will get a really high, incorrect reading.
3) Make sure that when you are reading the gauge, you are not filling it at the same time, if you do this you will get another astronomical reading. Close the Bottle, leaving it connected and then read the gauge.
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Cardinal Red '88 GT 5 speed, Cobra Upper/Lower, Dynomax complete Super-Turbo cat-back system, Turbo Coupe Rear 10" discs, 3:73 gears, SN95 Master Cylinder, Summit Racing adjustable proportioning valve, Spec Stage II kevlar clutch, steeda adjustable cable/quadrant, 73mm front calipers, P.A. Performance 130 amp alternator, 99 Contour Electric Dual Fans, Battery relocated, rebuilt 91 T-5, Mass Air conversion
the compressor ins't spinning is there any way to test it out? i really dont want to have to purchase a new one i hear they are really expensive... help
most likely your low pressure switch is holding out the compressor from engaging, if your looking at your engine on the passenger side near the fire wall there is a black canister, that is the accumulator, there is a pressure switch screwed into the tank with 2 wires to it, if you jump out the 2 wires and the compressor engages you know its the low pressure switch. give that a try, if not its gonna get a little bit deeper in trouble shooting
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1987 Mustang GT Convertible
1985 Mustang Drag Car Project
2007 Mustang GT
Too many mods and parts to list.....
the compressor ins't spinning is there any way to test it out? i really dont want to have to purchase a new one i hear they are really expensive... help
replace the clutch "hub" about $30 to $40 bucks..........5.0's are notorous for the clutch hub to be were out........
I found out that my low pressure switch was faulty on the accumulator. I replaced it but the compressor was then engaging in five second bursts about every ten seconds. I tried to charge up the system but even when the gauge on my fill bottle said the system was full the air still wasn't cold. After a while the low pressure switch seemed to almost go bad again as the compressor stopped comming on completeley. What is going on did I ruin the new switch already or somthing?
I found out that my low pressure switch was faulty on the accumulator. I replaced it but the compressor was then engaging in five second bursts about every ten seconds. I tried to charge up the system but even when the gauge on my fill bottle said the system was full the air still wasn't cold. After a while the low pressure switch seemed to almost go bad again as the compressor stopped comming on completeley. What is going on did I ruin the new switch already or somthing?
is your a/c clutch spinning freely when its engaged....
I replaced that low pressure switch after I found that by jumping the wires that the compressor started kicking on, but it still doens't work? what is going on?!
the low pressure switch shuts off the compressor at low pressure. when the compressor stops spinning the pressure will rise and engage the low pressure switch and on comes the compressor again. viscious cycle
that being said. if you do not have enough refrigerant in your system then it either wont come on at all....or come on go off.
the gauge is only acurate if the compessor is spinning.
did you do the 134a conversion? if not...you need to bleed the system out,134a and 112 dont mix...do the conversion(just a couple of fittings) install oil and new refrigerant until the gauge reads in the green.
do not connect the gauge without the car running and the a/c on.
it will take a couple of cans.
good luck
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89 5.0 convertable..paxton 6lb., flowmasters, full police strobe package,dual alternators w/second complete charging system, competition audio system w/18 speakers incuding
4-15" subs in a lexan enclosure
lowered and custom painted with a mustang airbrushed on the hood.
if you do the conversion make sure you remove the compressor and accumulator from the car and drain any oil that may be in them, r-134a uses a synthetic oil and r-12 uses a mineral oil, mineral oil is not compatible with r-134a and therefore will not move throughout the system and wont return to the compressor. no oil no compressor
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1987 Mustang GT Convertible
1985 Mustang Drag Car Project
2007 Mustang GT
Too many mods and parts to list.....
Air Conditioning Problem 
air conditioning 
