Hi everyone. First time poster here.
I'm trying to resurrect air conditioning that hasn't worked for some years in a 1997 C2500 Suburban -- single AC system (no rear air). I thought the system just needed to be recharged, but it has proven an exercise in "chase the problem." Took it in for a recharge with die, the compressor started short-cycling again within a few days. Fine. The shop found the presumed leak and filled again for free.
However: more short-cycling. Well, there was a leak at the compressor, and the compressor itself was showing resistance (which made sense -- you could feel it in the steering wheel whenever it kicked in). Fine. New compressor, not too bad for price. Got to short cycling yet again. Had another leak at an o-ring the shop replaced and recharged for free.
More short cycling! This time, evidence of leakage at the condenser. Ok, it's starting to get more expensive than I planned, but fine. Replace the condenser.
Well, that brings us to the present situation. Now everything seems to be working mechanically. For the first time ever, the compressor kicks in and runs all the time, no cycling at all. That's kind of what I wished it would've done in the past, because the air never got extremely cold, even right after the (ultimately failed) recharges. It felt like it was cycling off too fast to get really cold. But I thought it was supposed to cycle some at least. And now, the air is not getting cold at all. It may be very, very slightly cooler than plain vent, but it's close enough that I'm wondering if I'm just imagining a difference. In any case, that's obviously not right. It's strange and seems to point to something -- but what?
So what would you look at next? From all that I've read, this could indicate a plugged orifice tube or a problem with the evaporator. But as I'm amateur, I don't know if one or the other is more likely, or if it's something different altogether. Again, why is the compressor on all the time?
If you're talking evaporator, it sounds like a person would have to pull down the dash, which gets you either into a seriously long project for an amateur, or very high price job, even at the reasonable shade-tree mechanic rate. For a 23-year-old truck. Now, the good of that is I could have the blend doors themselves replaced at the same time, as the air flow is weak and I'm leaking air to the defrost vent no matter the setting. Yes, I've done the remove-the-blower-and-clean-out-the-junk trick. And the blend door actuator itself is working (replaced it recently myself). But if you're talking like a $1500 bill, maybe it's time to plow that amount into a somewhat newer Suburban, maybe a GMT800. But of course then you inherit a whole new set of problems.
I'd love just to get the AC blowing ice cold, and make my own "blend door" by stuffing a towel over the defrost vent when not needed.
So what would you do? Try the orifice tube replacement? Replace something else? Bite the bullet and have the full dash removal project done? Invest in a newer truck and relegate the '97 to 3-season duty? It's such a great family hauler, hate to lose it for summer trips.