can i do anything to diagnose duo-therm dometic penguin?

i guess caps were OK

shop said compressor was running, so they ran a half hour or so.

after this, he said the compressor had stopped. so, just like we had determined after a good run, no cool air.

i think they mean there is no freon, unless they mean compressor is weak...but they say $1000 for install of new upper unit is verdict.

we hardly ever run the AC except to put a load on the genset which we only run to exercise the genset!

i want to look into one of those very compact wall AC units you see in tiny TTs like T@B. or some portable cooler. these might be useful for a few hours a year, at most. we go to local SPs late sept thru early may

Your model number makes it a 13500-BTU unit. There was also an 11000-BTU Penguin which presumably would cost a little less. By that I mean "Less Expensive" - We're talking "RV" here, about as bad as talking "Boat" or "Pool."
The hole just about all of them mount on is 14 x 14 inches so in that sense they're all interchangeable. BUT...

...and it's a BIG BUT... RV A/C units are now being sold almost exclusively as individual Upper and Lower components. IF IF IF your Upper is "BAD" (and I'll get to that in a minute) then the least expensive solution is most likely another Penguin Upper. Just hope that Dometic hasn't superseded your design to where the current version of Upper isn't compatible with your older version of Lower.
"BAD" to me, in an RV A/C Upper Unit is a Failed Compressor --OR-- coils leaking refrigerant. Compressor and Coils are the Hermetically Sealed (hence "HERM" on the Run Capacitor for Compressor). Anything less than the sealed system (fan motor, fan blade, capacitor(s), controls) I would attempt to repair or replace.
Yes, your existing thermostat should still be able to control the Furnace. Sometimes a residential thermostat from Big Box or Walmart can be used with very good results at a very minimal cost.
You have a two-way RUN Capacitor. It is in fact possible for ONE "side" of it to go bad and the other side still run its component. At home, I have had the HERM side go bad (no compressor running) and FAN still good. I have also had the opposite. Come home to an overheated compressor because the FAN side of the capacitor had failed.
The BLACK capacitor you describe is Start Assist. WITH POWER OFF, Yes, you could short the terminals without burning anything, then disconnect them and see if it would start with just the HERM side of the capacitor. The Assist is for when supply power degrades, like low campground voltage, using a generator, or perhaps very high outdoor temperature. But Compressor will NOT run if HERM is bad.
$55 to troubleshoot is probably a half hour at the dealer's labor rate, not at all unfair. If you want to take his estimate under consideration and discuss it here, feel free.
If you feel uneasy about getting up there, into it, around electricity, then please follow your gut and have somebody else do it. I'd help if we were closer. Nothing on that RV is worth risking life/limb. I fervently believe that. I just need to work on following it...

well. i have taken in a lot of info from your help and related googles to know that i cannot diagnose this given my limited abilities in HVAC fixin', phobia of electronics i don't know, and low visual acuity. just attemptind to replacing the two caps exceeds what i am comfortable with.

my RV dealer says they'll diagnose for around $55 - a bargain to me.

my only question now is if this ducted sealed refrigerant penguin model 600315.321 unit is needing to be replaced, is there a simpler budget model AC that would easily fit in its place. less BTU, non-ducted w/ ceiling controls are fine for us - we seldom need AC but for summer exercise restaurant/park day runs. also, the wall duo-therm thermostat still needs to work the propane atwood furnace...so can the thermostat on wall still work atwood alone?

thanks for advice

i am appreciating the help...

without disconnecting brown wire from the silver RUN capacitor, can i still just run the AC and feel compressor tubes for heat/cold and determine something?

if so, from my pics, where should i put my hand on compressor or its tubes?

in the caps pic, what is the black thing in the upper left?

since the the blower fan works on hi and lo, is the black COMP/START capacitor w/ the red and white wire the more likely cap to be the prob if compressor is not right?

if i short the red and white wires atop the black capacitor w/ a plastic handle screwdriver, will it melt the wire connectors to te capacitor terminals?

also i am wondering what behavior would tend to indicate a control panel issue?

Some great replies!

Tried to look up the ratings of the Capacitor. I can tell you the FAN side is "10" which is 10-mfd, 10uF, or however it's expressed. Ten MicroFarads. You can see the "10" below "M" in "A.O. SMITH" in one of the photos.

Would be best to loosen the strap around the Capacitor and read the uF value off of it. Might be 35, might not. You can get a single capacitor with the correct value for the Compressor (might be marked COMP or HERM) and disconnect HERM from the combination Capacitor you have now. Connect that to the single value one, but you'd need to run a jumper between COM on the existing Capacitor and the other terminal on the new single one.

It also has a Start Assist Kit on it. That little black capacitor is probably 88-108uF, and there's a PTCR device with it. You can see those in the wiring diagram. You shouldn't need those in circuit to start the compressor on 30A shore tie, but the HERM side of the Capacitor has to be there and be good.

I'm good at this part of the A/C, not so much on Controls and the Control Board. Compressors fail, but not as often as you'd think. Capacitors fail often enough that I keep spares on board. But I'm not much help on the controls. Fortunately for me, our A/C (Coleman Mach) is not a ducted unit, so it doesn't have a wall thermostat, control board etc.

Anyhow, I've got this nagging feeling your problem is in the controls. Still worth it to check/substitute the capacitor. Some meters can test capacitors but you've gotta get a little upscale from the Harbor Fright freebie and the like.

So far I've found this manual which includes parts information and a wiring diagram.

If you disconnect Brown or White from the FAN or COM terminal of the Capacitor,Fan shouldn't run and you can listen for Compressor.

In the middle of a project right now, back later...

The last picture is of use... the larger capacitor is probably a 35/5 uF. Buy a new one and put it in... even if it does not solve the problem it's good to have a spare. Next is the control board... probably a 310 9229.009 which is still in production at $140.

capacitors were behind the panel with wiring that is figure 4 in my previous post.

i can't really tell what is what here. i also did not see how to disconnect blower motor.

martha took these exciting pics. one of the labels has a duo-therm model #

i do not know where the capacitors are. in p1c #10 on the end of the compressor i see a small cylinder - is that one?

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