Cadillac Repair: 1991 Cadillac Eldorado - Reset A/C Compressor, cadillac eldorado, twilight sentinel

Question
Change to my previous question (see * in codes for correction), sorry:

Having problems resetting the a/c compressor on a 1991 Cadillac Eldorado, 4.9 V8.  I'm converting R-12 to R-134, bought a kit from Advance Auto.  As you know, the manual states the compressor must be ON to charge refrigerant.  Of course the computer shuts it down.  The codes are as follows when I hold OFF and WARMER:

E046 HISTORY
B120 HISTORY
B121 CURRENT*
B122 HISTORY
B446 HISTORY
B447 CURRENT
B552 HISTORY
R061 HISTORY

Could you lend a hand?  It's 100+ degrees where I am and I have 4 cans of R-134 just waiting!

Answer
B121 = Twilight sentinel enable problem.

B447 = Very low AC pressure.

You need to jumper the AC relay in order to engage the ac compressor to install the freon.

Then CLEAR all the codes from the computer.

I can provide pictures and diagnostic procedures if you e-mail me at: onlineautohelp@msn.com.