I had the exact same problem in my 93 DX. It happened one summer when I started using the A/C again after the winter. I replaced two or three fuses with the fuse blowing after a few minutes. I traced all the wiring back from the fuse box to the compressor, cleaning any contacts with electrical contact cleaner. I hooked up a multimeter to the ac clutch fuse bay and monitored it to see when it would come down. It was after cleaning the relays and contacts that plug into on the drivers side of the engine bay that I noticed it drop. They're near the power steering fluid resevoir covered with some sort of plastic or something, probably to protect them. One of them must be responsible for the ac clutch because after I unplugged all of them, cleaned the contacts and put them back, the meter dropped and the next fuse I put in never blew. I'm not sure what I did but it fixed the problem.

As for the lack of cooling, make sure the system is at the appropriate pressure. Most people think if they just add a ton of coolent that they're good to go, but if the pressure is too high (too much refrigirant) the compressor will kick off too soon after it engages to prevent damage. You can can get an AC pressure gauge at an auto parts store, similar to a tire pressure gauge but with an attachment that fits the low pressure line on your AC that will give you the pressure of the system. A hayes manual or helms will give you the appropriate PSI for the system, I believe it's in the range of 25-40PSI. Too high is just as bad as too low. If you've got a leak, I'd get it fixed. If not for the hassle, for the environment. That R-12 crap is no good. Get it fixed, flushed and retrofitted with R-134. It will cost a few hundred bucks but I think it'd be worth it.

I don't know if you've had a similar problem, but my 93's fan was always really weak. While the A/C was ice cold, it didn't blow very well. I don't know if I needed a new fan or what.

Good luck!