WackyWormer

I have a 97 Mustang GT. In the past few weeks i've been getting a lot of noise from the A/C clutch. It makes a loud squealing noise on startup for 2 secs, then is fine if i have the A/C off. If I turn it on, it makes progressively louder squealing noises everytime the clutch engages, til it gets one that's really loud, then starts the process over again. I just replaced the compressor, clutch, and drier ($325!!!!) and its doing the exact same thing. HELP!!!

Sunadaime

i only does it when ac is on? no squealing with it off? i would say idler pulley but this doesnt sound like it. could be your blower freezing up. check that yet?

WackyWormer

yep, only on, except for the initial startup... haven't checked the blower, but could a bad harmonic balancer do this? the crank pulley doesn't really seem like its running true. Also,when the a/c is on, the air is really cold... dunno if that rules out the blower theory

Sunadaime

yeah that would rule out the blower. im not educated in this but i had squealing on another car. ended up replacing the blower motor and relay. but it doesnt sound like that. dont know about the other pulleys either. Hope you figure it out. But thanks for reminding me to get my ac charged

WackyWormer

Any other ideas?

Churchkey

Sounds like a blockage in the AC lines. Find the orifice valve, it should be located in the high pressure line & pull it out its probably plugged with debris from the last compressor. Its standard practice to replace that valve when the compressor is changed.

Also,did you check the oil level in the new compressor? you may have installed it without oil in it.

WackyWormer

I put the required 1.5 ounces in the compressor, but where is the orifice valve? I know it was supposed to be replaced, and i bought one, but neither my dad or me could find it. Can you be more specific about where its at?

Churchkey

I have not done much service work on drivers/factory systemsfor a # of years. Most of the AC I work on is complete installations in street rods, customs & kit cars.
This is general information that may help you get your system working.
I don't have a shop manual for your car however the orifice valve is somewhere in the liquid line. Suggest stopping at Ford & have the parts man bring the liquid line & orifice valve up on screen to find where its located.Or you can search for it if you have the spring lock tools. Blow the AC charge & remove the liquid line fitting at the firewall. This is the one that connects to the evaporator, its next to the accumulator/dryer. Look into the line that goes into the firewall the orifice valve may live there. If so remove it with long nose plyers. If not remove the liquid line from the vehicle the oriface valve is probably located mid way in the line. If memory serves I had to replace the entire liquid line on one 90's Ford I serviced in order to change the oriface valve. Its been awhile. While you have the liquid line off also remove the suction line from the acculumator. Blow shop air into the liquid line at the evaporator& check the outlet of the accumulator/dryer. You need good air flow through the accumulator, its possible you may have a blockage there.
Also, when you have the lines disconnected remove the AC belt & turn on the key but do not start the engine. Turn on the AC & manually rotate the AC pulley. It should turn with a bit of resistance but be smooth. If its tight or feels like it has tight spots you may have a bad compresor.

shabba1990

I have a 97 also, and I had that same problem!! After I changer the compressor and everything ,come to find out that my harmonic balancer was F#$%ed up ! On the original one, there is a rubber center that was all cracked and brittle. It wouldnt make any noise until I turned on my a/c, then once it was under a load it would squeel like a mad pig! I saw it moving back and fourth on the crank while the engine was running. I pulled the balancer off and it seperated in my hand. Check that out it was easy to change and was only like 60 dollars.Good Luck!!!!