Hi folks,
I'm not very good with electrical diagnostics and need some help. My vehicle is a '95 Zetec Mystique; the problem is that I do not have A/C. All blower speeds work. The system is charged with refrigerant (I checked with a gauge). The last time the A/C worked was last summer. Operation would be intermittent between sessions, i.e. it would work one day but not the next; outlet temps would not change during the same period of operation. The outlet temps were consistently cold, so it didn't seem like a refrigerant leak.
If I remove relay R4 from the power distribution box and connect pins 3 and 5 with a paper clip (thanks to the archives for this trick), the following happens:
- the A/C clutch engages;
- low-side pressures dip down to the 20s, then rise slowly to the 40s, then back down to the 20s, and cycle;
- the electric fan only comes on when the low-side pressures are in the upper 30s and 40s;
- the air coming out of the vents (knob setting on Max A/C) is cooler but not cold.
I replaced the yellow relay and flipped to "Pinpoint Test D" starting on page 12-00-34 of the 1995 Contour/Mystique Service Manual:
Step D1: The A/C clutch does *not* operate with the engine on and the damper door switch set to Max and the blower motor switch set to High... so I moved to Step D2.
Step D2: Do I need to crack open the climate control assembly within the cabin of the car to assess Circuit 14S (P/O)? I noticed that one of the wires connecting to the cycling switch is on the same circuit. Will it be an electrical equivalent if I measure voltage there?
Thanks in advance for your help; it's starting to get hot again here in New England.
Po
