A/C Not blowing Cold Air

[CapnCampn]

Greetings Tech Team!

I have a question regarding my father's Air Conditioner - It is not blowing cold air when turned on.

The fan runs at full speed which I *think* also turns the compressor, which we can hear turn on also.

I pulled the shroud on the top of the trailer, and felt the copper pipes while it's running, I found one that is cool and one that is warm but they are definitely not hot and cold like I would expect.  I also found a bit of oily residue on top of the ?dryer? cylinder, which makes me think there was a freon leak causing the issue.  
I'll try to upload a picture later...

He took it to a service place this week, and they claim there is a short causing the problem and quoted 1800 for a replacement.  

I'm not sure what short would allow the fan to blow and the compressor to run while not giving any cold air.

He's thinking a second opinion is in order, I agree - what says the forum? 🙂

Thanks!!

CC

[CapnCampn]

Well, he decided to just order a new one since anything compressor related is going to pretty much require replacement anyway.  In my prior glance at it  one pipe was cool and one pipe was warm going into/out of the compressor after running for a few minutes, so I'm pretty sure it's a freon issue.

Thanks to everyone for the ideas and feedback - I'll try to reply with a successful repair note!

CC

[opnspaces]

No schrader valves on the RV air conditioners. but I have read about some people soldering or braising some on.
It sounds like unfortunately you are going to have to verify everything the tech said. Maybe it's as simple as the start capacitor is blown and the compressor is not even starting

[CapnCampn]

Thanks team!

The diagnosis from the tech was that the compressor winding was showing continuity to the AC case, so they are saying it's shorted.  I'm planning on confirming this diagnosis soon when I can get back on the roof.

I was looking at replacements, and yes, 800-1000 seems to be the going rate, would probably be worth just swapping it at that point.  I didn't notice any schrader valves to check pressure of the unit - is that a thing on RV A/Cs?

Thanks again, 

CC

[valhalla360]

If the fan and compressor are turning, it's not likely an electrical issue. It might be a freon leak (or whatever they are calling the replacement fluid).

The replacement quote seems high. A 15k air/con unit is $700-1000 depending on brand. Replacement is disconnect a few wires and 4 bolts, pull it out, put the new one in and reconnect the wires & bolts. 

[CapnCampn]

Ok, a little update... I forgot to mention it's a Coleman Mach (Probably Mach III, not sure at the moment).

I was looking at some parts views, and I see the fan motor only runs the condenser fan and the blower fan.  The compressor is it's own little unit (bigger cylinder) , attached to what I think is the dryer (a small cylinder). 

I'll try to get some time tonight to double check if the compressor is actually firing up.  But either way, if it's a freon leak or if it's a compressor electrical, it might not be fixable.  

Still open to opinions & diagnostic ideas though! 🙂

CC

[StirCrazy]

thoes compressores are disposable, they can be fixed but it is normaly not worth the time or money.  yes it could be shorted out electricaly which means it needs a new compressor.  I would get a few different quotes on that though.  you shoudl be able to have just the compressor swapped out instead of replacing the whole thing, but even at that, 2000 seams a little expensive unless you live in canada and thoes are canadian bucks.