93 Ford CV: new A/C compressor does not cycle

[pgranvil]

Hello,

I just replaced the A/C compressor/clutch on my 93 CV. The old one worked and the A/C worked fine and was cold, but the compressor was starting to make noise and it was diagnosed as a bearing about to give out. So rather than wait for that to happen, I opted to replace the compressor/clutch unit with a new OEM one from Ford.

Now the A/C is cold, but on a long drive and after a short while (maybe 30 minutes) the air flow drops significantly. I've noticed that once the A/C is turned on the compressor does not cycle, it stays on for as long as the A/C is on, and shuts off only when the A/C is turned off (ie, switched to OFF or VENT). Once the flow drops off, I turn off the A/C for about 30-60 minutes and after that the flow returns to normal.

Everything worked fine before the new part was installed. Any ideas why the new part may not be cycling? Is there a connector that may not be making good contact? or is the cycling an internal function of the compressor?

I can confirm that the old compressor did cycle ok as I watched it prior to the new part being installed.

And unfortunately, I can't go back to the garage that installed the part because it was installed one day before the long drive, and is now 1700 miles away... (sigh)

Thanks,
Paul

[reekor]

Before you had the work done your ac might of been alittle low on refrigerant, Your ac is made to kickin around 50psi and kickout around 25psi. Refrigerant extremely expands the hotter it gets and extremely contracts the colder it gets. When your AC is running the refrigerant gets cold and looses pressure and if it gets cold enough to drop below 25 psi the compressor will cutout, and as soon as it heats up again to hit 50 psi it will trigger the compressor again. On a 80F day or hotter the ac compressor should run non-stop. Check it out on a cool day it should cycle on and off 65-70F. As for your airflow problem, I would try replacing the heater motor, it sounds to me that it’s losing rpm when it gets hot. The only other thing it might be, your system might be overcharged and freezing up the evaporator. Most places will put a gage on your system free of charge or you can buy a gage cheap at any autoparts store, in the USA.

Originally Posted by pgranvil

Hello,

I just replaced the A/C compressor/clutch on my 93 CV. The old one worked and the A/C worked fine and was cold, but the compressor was starting to make noise and it was diagnosed as a bearing about to give out. So rather than wait for that to happen, I opted to replace the compressor/clutch unit with a new OEM one from Ford.

Now the A/C is cold, but on a long drive and after a short while (maybe 30 minutes) the air flow drops significantly. I've noticed that once the A/C is turned on the compressor does not cycle, it stays on for as long as the A/C is on, and shuts off only when the A/C is turned off (ie, switched to OFF or VENT). Once the flow drops off, I turn off the A/C for about 30-60 minutes and after that the flow returns to normal.

Everything worked fine before the new part was installed. Any ideas why the new part may not be cycling? Is there a connector that may not be making good contact? or is the cycling an internal function of the compressor?

I can confirm that the old compressor did cycle ok as I watched it prior to the new part being installed.

And unfortunately, I can't go back to the garage that installed the part because it was installed one day before the long drive, and is now 1700 miles away... (sigh)

Thanks,
Paul