Here is a post from another DIY site:
Ford Escort VERY HIGH A/C Pressure!
I got a re-chill kit to inject some Refrig into the low pressure port of my '99 Escort today. Before trying to recharge, I checked the pressure with the guage. I started the engine, turned on the A/C to max, and installed the guage hose to the low pressure port. The needle swayed back and forth around 50 psi, then SHOT up to the red to 80 psi and blew the gauge attachment off the car! The needle had pegged at 80 psi. What could possibly cause this to happen?
I won't turn the A/C on now until THIS gets fixed. I noticed the A/C would run well for a minute, possibly two minutes, then be gone and feel just ambient air coming from the vents. Then it would come back after more rpms were given to the engine.
End of copied post
You will have to ask the moderator for the purpose of this site. If you look at my posts you will see that I always try to help people do their DIY thing if I happen to know something which will help. I seek help more than I give so getting help from others is very important to me. Part of helping people is telling them straightup if it appears they are trying to do something well beyond their scope, especially if it has safety implications. If you think I am out of line, please ignore me and help the OP fix his AC system.