Help! 2018 Tab 400 - CoolCat AC & Refrigeration Problems

cowboypete

I bought my 2018 Tab 400 new.  Both the AC & Fridge went out on the end of our last trip. No obvious power problems at the site.  I assume there are fuses or breakers for both. Can you tell me where to find them and is this the best place to start?  Thank you!

MuttonChops

@cowboypete ;  yr-2018 was the first TaB 400 production and there were many production changes during that build year.  It would be very helpful if you could provide more information on your specific unit build:

  --  Fridge type 2-way, 3-way.  Model number would be best.

  --  Air Conditioner type; Air8, CoolCat, ??

  --  Does your unit have factory, aftermarket, or no Solar Panels?

pthomas745

Look inside your converter down there near the floor and have a look.  That is where the breakers are.

Are your outlets working on shore power?  It may be something as simple as resetting the GFCI outlet.  Is the Alde working on electric?

Here is a thread with the same sort of issue.  Don't let this other owner's issue distract you...but there are some nice photos of what to expect inside the converter.

https://tab-rv.vanillacommunity.com/discussion/13487/shore-power-not-working/p1

cowboypete

Thank you for your response.The refrigerator is by Norcold and is a 2-way AC/DC.  The model # is NR751BB.  The AC I believe is a Dometic or CoolCat, but I do not know where to find the model #, yet.  We have factory solar panels.  Thanks again. 

cowboypete

to pthomas745, The outlets are working on shorepower.   The Alde system lights up and we have hot water.  I have not checked the breakers yet, that will be on Monday. I've started reading the thread you sent, I will let you know when I get to the pictures. Thank you.

MuttonChops

cowboypete said:
. . . 2018 Tab 400 new.  Both the AC & Fridge went out on the end of our last trip.

. . . [120VAC] outlets are working on shorepower.
. . . The Alde system lights up and we have hot water.

The Alde and CoolCat require both 120VAC and 12VDC to operate (when Adle is set to Shore Power Mode).
The 2-Way Fridge on most builds only needs 12VDC to operate.
Your Adle functioning correctly while the CoolCat and Fridge are both dead does suggest a 120VAC Breaker or 12VDC Fuse failure.

Suggest step one:
  --  Turn-off all equipment.
  --  Flip Main 120VDC Breaker to off, it is the 30-Amp on far left of Power Center.
  --  Next one by one flip off each breaker to the right of the 30-Amp, pause a moment and flip back to on.
         This operation will ensure any breakers that tripped but don't appear to be tripped on back on.
  --  Flip Main 30-Amp break back on.
  --  Will CoolCat and or Fridge operate now?

If step one did not fix everything, step two:
  --  Turn-off all equipment.
  --  Flip Main 120VDC Breaker to off, it is the 30-Amp.
  --  Set Battery Cut-Off Switch to Off.
  --  Pull each Fuse, one by one, is it good or blown . . . re-install or replace.
          A visual inspection of the little wire in the fuse body should work, an Ohm-meter test
          would be best.
  --  Leave the Battery cut-off switch Off, power back up on shore power, test Coolcat & Fridge

For reference, simple diagram of typical power distribution:

Jilong

@cowboypete I have the same 2018 Tab 400. This is a photo of my WFCO panel under the closet door. I've circled the circuit breakers that are marked for my Coolcat and fridge. It may be differently wired on yours, so check the stickers next to the breakers in your WFCO. These breakers are relevant only when you're on shore power, but they should both be in the ON position.

Jilong

On a related note, the right side of the WFCO panel contains all of the DC fuses. If there is a red light next to any of them, then that fuse needs to be replaced. You can get fuses at any automotive store, Tractor Supply, or sometimes at a Super Walmart.

MuttonChops

Jilong said:
. . . the right side of the WFCO panel contains all of the DC fuses.
If there is a red light next to any of them, then that fuse needs to be replaced.

@Jilong & @cowboypete ; The bad Fuse Indicator (LED) is not a reliable indication of the fuse status.  For the LED to turn on something connected to the circuit must be switched on.

For example; if the Ceiling Fan was the only item on the circuit and the circuit fuse is blown, if the Fan Power Switch is On the LED will be on - - - as a path to ground is provided. But if the Fan was switched 'off' the Fuse Indicator would not turn-on.  So something like the Fridge that has a digital control panel may not allow the LED to function (no power at the Fridge control panel for the digital switch to activate).

For that reason a visual or ohm-meter inspection of each fuse is needed.

Jilong

@MuttonChops Thanks for the explanation, and I'll keep that in mind the next time something stops working!

For the 2018 Tab 400 that @cowboypete has, if it's the same load out as mine, it's has the 2-way fridge that does not have any digital display, but the Coolcat does have the digital thermostat that's wired to the DC circuit, so he can check the fuse marked for the Coolcat to see if it's bad.

cowboypete

I have checked the breakers and the fuses and they are all good.  What should I do next?

Horigan

Both the frig and Coolcat plug into an AC outlet in the Tab.  Unplug them and either put an outlet tester in the socket to confirm it's getting power, or run an extension cord with known good power and plug that into the frig and Coolcat to see if they operate.  This will at least tell if you're getting AC power to the units.

cowboypete

Thanks everybody, that is a lot of good info.  Let me get to work right now and check it out further.  Thanks again, as Arnie says "I'll be back"

cowboypete

Sorry for the delay in getting back to you.

I've gone through the steps of checking the breakers and fuses and methodically flipping the breakers back on.  the refrigerator is now working. next question is what is the coldest setting 1 or 5 ?

I still cannot get cold air out of the AC.  It blows air but it is not cold, just room temperature. Next step please. Thank you.

Marceline

5 is the coldest setting. Here’s the manual: https://norcold.com/wp-content/uploads/2018/06/norcold-nr751-ac-dc-refrigerator-owners-manual.pdf

Jilong

cowboypete said:

I still cannot get cold air out of the AC.  It blows air but it is not cold, just room temperature. Next step please. Thank you.

We had this problem just yesterday in our 2018 Tab 400. I had forgotten to remove the cover over the grill of the Coolcat on the outside driver's side. After I removed the cover, I waited a while to let the compressor cool down, then set the Coolcat to cool auto at 60°F to ensure the compressor would kick in, and I received cold air again.

qhumberd

On my 2019 the CoolCat has modes for fan only as well as cool. Make sure you are in the auto fan cool (snowflake) mode by cycling thru the display options, then wait for it to turn on. In normal operation the fan starts running for about 15-20 seconds, then you hear a lower sound which is the compressor turning on. Cooling begins then. If that is not the sequence then compressor is not starting. Typically AC units have a starting capacitor to handle the initial load of starting the compressor and they can fail. A capacitor should be easy for a tech to replace. The worst case is a loss of refrigerant or a failed compressor, which are harder to repair and I have read many techs will not work on them.

good luck

manyman297

@qhumberd suggestion is spot on. A lot of people don't realize they're just running the fan and not actually in cool mode. 

Aside from failed compressor or refrigerant leak another catastrophic (but repairable) issue could be that your capacitor has failed. Not super likely since these units don't get used a whole lot but it could've been faulty from the factory.

cowboypete

An after thought I had was that I cleaned the inside filter on the AC the week before we went camping and we found out that it wasn't working.  Could I have done something, like knock something loose, etc?

Thanks for all of your help so far!

qhumberd

Cleaning the filter should not have put you that close to any components that would cause the symptoms you described. Any results on the other checks mentioned?

cowboypete

Sorry, I've been tied up, Hopefully this afternoon. Bob