Cadillac Repair: cadillac AC, r134 freon, economy mode

Question
QUESTION: Our Caddy "which is 1988 Seville" had the A/C service light come on and the "Auto" setting would automatically jump to "economy mode". There is no leakage of freon, the computer has been cleared and reset, relays (black box, under the hood) checked, but we still have the same problem.

1. Are you getting ANY CHECK ENGINE light illumination on the dash ?.  YES

2. Does the A/C compressor turn ON (engage) at ALL ?.   NO

3. Does the interior blower motor operate ?.   YES

4. Does the blower motor work on ALL speeds ?.   YES

5. Are you getting air flow from the dash vents, the defroster vents and the floor vents ?.    YES


Can you help

ANSWER: What code or codes are you getting ?.

Did you convert the A/C system from R-12 to R134 freon ?.

---------- FOLLOW-UP ----------

QUESTION: as far as codes i do not know any of the codes

and as far as the converting the a/c to r134 i have not.

Answer
Do NOT try and convert the R-12 system to R-134 because the low pressure sensor is not made to handle the R134 freon and will cause the check engine light to come ON and you will have no AC compressor engagement.

To get the codes Turn ON ignition key.:

1. Push and hold the OFF and WARMER (^) buttons on the climate control panel for 3 seconds and release them.

2. On the fuel data display tell me EVERYTHING that you see as if you were video taping it. The display will stop at ECM?.

3. Turn ignition OFF