Air Conditioner Question

[Jerry 5TJ]

Valuable thread with info on complexity of troubleshooting AC in airplane with all of its distributed parts.  

[carusoam]

Great problem solving thread, and follow-up!

Best regards,

-a-

[Yetti]

14 hours ago, Txbyker said:

Fixed.  I am posting this in case future MooneySpacers have the same issue.  Symptom - cockpit fans blow.  Air starts cool, then turns to ambient if not warm.  Freon and pressures normal.  AMP draw is nominal.  Issue - Blower fan that cools the recirculating freon in tail not operating.  Fix - measure voltage of relay located under blower breaker in tail. Check fan voltage and check bus voltage to relay with switch on and off. Kissling part number 26.72.03 price $179.  

Russ

Glad you figured it out.   Betting that relay is a pain to get to.  Not liking the tywrap job. remove the black tyrap to the larger wire, just going to create vibration. The little wire over on the right.  It's going to vibrate out of the ring terminal.   wiring should be smooth with no sharp bends.  properly supported.   Nice clean ground though :-)

[Txbyker]

6 hours ago, Yetti said:

Glad you figured it out.   Betting that relay is a pain to get to.  Not liking the tywrap job. remove the black tyrap to the larger wire, just going to create vibration. The little wire over on the right.  It's going to vibrate out of the ring terminal.   wiring should be smooth with no sharp bends.  properly supported.   Nice clean ground though :-)

It’s unbolted and swung from under the mount and hanging by the leads temporarily in this photo.  Black tie wrap I put there to support it during surgery.

[Lee A.]

Russ,

Thanks for the post.  My plane has been back from annual for a couple weeks.  I’ve noticed today that I’ve lost my AC also.  Will check it out with Brian next week.  

[kmyfm20s]

Mine was similarly cycling cool and ambient temperature air. My compressor fan was working but I needed to open up the expansion valve to correct the problem. The maintenance manual has/had a error and states a higher amount of R-134 than what is required. Charge the refrigerant levels by the pressure gauges and not by weight. If it’s cycling after your with in the proper pressure limits of refrigerant and the compressor fan is working adjust expansion values usually by opening them to stop the cycling. Recheck the pressures after the adjustment because they will change. The hotter the weather the better for charging your system by pressure gauges.