Geriatric Pathfinder A/C System

I began troubleshooting the A/C system on TWUCK.

Does the compressor turn by hand? Yep. That’s good.

Does it turn when commanded by the computer? No. That’s not good, but we can override it and see if the magnetic clutch engages. It does. That’s good. Just means that the sensor sees no pressure or too much pressure.

So… what’s the refrigerant pressure? 0 psig. Hmm… not good. Let’s give it some refrigerant…

It takes pressure… and promptly takes 25 psi of refrigerant. Also good. The pressure sensor detects pressure (also good), and the ECM triggers the pump (also good) and… pressure drops. Not good. Within a few minutes, it’s down to zero. That’s annoyingly bad but means there’s leakage in the lines, or condenser, or dryer, or the expansion valve, or the evaporator, or in the compressor*.

There is R134a refrigerant with a UV dye which is well-suited to tracking down A/C leaks. But I haven’t any. So it’ll be another trip out to the parts store to see if I can find a R134a UV dye penetrant. It’ll wait until another time.

Eventually, I’ll have TWUCK’s AC system fixed. Eventually.

Once fixed, in no particular order, it’s on to…

  • Shocks — front and rear
  • CV joints
  • Ball joints
  • Windshield
  • Weather stripping
  • Antenna
  • Stereo
  • Find a way to incorporate some cabin air filters

I’ll have to prioritize that list… and include anything else that I happen to stumble across.

Gosh, I mean, sure, some things need to be repaired from wear and breakage over time. But I’m not sure if it’s worthwhile to set right everything neglected on a 23 year old automobile.

*Knowing that it’s been effectively stationary for a couple of years, I’d wager that the seals in the pump have deteriorated (most probable) and the pump will need to be replaced with an overhauled unit. About $200-ish. Easy enough to replace. Then another $50 in refrigerant. But I’m not going to start throwing parts at it and hope that maybe guesswork pays off and instead work through it somewhat methodically.