When i saw the post my first thought was the click clack problem. It is a known issue. There is a TSB on it. I never bothered to fix mine on my 1995 because I read somewhere it is not harmful, just noisy.
Here is a link to the known issue for my year. You can find yours by doing a search.
Automotive Recalls and Technical Service Bulletins for 1995 Ford Truck Ranger 4WD V6-182 3.0L. Provided by ALLDATA
01-21-2 OCT 01 A/C Clutch - Loud Engagement Noise
But they want $$ if you want the info to fix. Someone here may know what to do but Ford seems to have known about the issue and what to do.
You can also check with your dealer, if they will give you the info.
EDIT: Of course the hiss, I don't know. The clutch click clacking might be this, in my totally unprofessional opinion.
95 Ranger Styleside SWB 4X4, 3.0, Auto, 4.10, 145,000 Miles
Century Cap, BF Goodrich All Terrain 30x9.50's, Reese Hitch, K&N Air Filter, Taylor Wires, Splitfire Plugs (I have had good luck with them), Bed Mat, Upgraded to factory alloy rims from "argent wheels", Cat, Dynomax Cat Back, Additional Battery Charging System, Transmission Oil Cooler, Grizzly Grill/ Brush Guard, Hella 500 Amber Fogs, Chrome Diff Cover, Nerf Bars, new bumper.
Upgraded to NH registration from Mass (Best upgrade!)
OEM Tube Rear Bumper, Tow Hooks, 31x10.50's, Larger or Additional Fuel Tank, Locker