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AKIQPilot · 03-18-2023, 03:25 PM

I'm having trouble with my Norcold 4 door fridge. I know right, who would have ever guessed.

Just a little background. Fridge and Moho are 17 years old. For the last 7 years we have spent from Oct to May living in the coach full time in Arizona. The fridge has never given us even one problem and even works decent in 100f AZ heat but that is about it's limit. It's completely stock with the exception of the Over Temp limit switch which was installed by a dealer when the recall came out.

I operate the fridge in Auto and am almost always plugged into shore power or a pedestal.

Last night I turned the main 12vdc lights on in the living room and I heard the fridge relay click and the fridge shut off. The living room lights were bright like always. I checked the house and engine batteries and both were right about 13vdc on the digital gauge. Over the next minute I could hear the fridge relay cycle on and immediately back off like the fridge was trying to fire up. Seemed like it might be a problem with the AC receptacle the fridge is plugged in to so I ran an extension cord from shore power directly to the 120vac fridge plug. No Change. The over temp control box looked normal with no lights on. I messed around with it a little more but it was dark out so I decided to just follow up in the morning. I turned on the TV and turned off the main living room lights. A few minutes later the fridge is back on and everything is looking normal. I shrugged my shoulders and thought "well it must have fixed itself".

Watched TV for a bit and went to bed. Fridge was fine. Woke up once during the night and fridge was fine. Freezer and fridge inside temps perfectly normal. Woke up this morning and fridge was fine. House batteries showing about 13.4vdc. Turned on the bathroom and kitchen lights. House batteries showing about 13.1vdc Fridge is fine. Turned on a couple more lights and house batteries showing 13.0, boom fridge turns off and relay begins to cycle on then immediately off about every 15 seconds. Turned a couple of lights off and the fridge fires right up and works properly.

At this point I have it narrowed down. It was still dark out but I assumed I had low voltage going to the control board. Maybe a bad connection, maybe a bad house battery, maybe a bad ground, but I had it narrowed down.

The sun comes up, I grab my trusty volt meter and with the help of my wife I prove that the batteries are good. The converter is putting out good voltage. The 12vdc power wires going to the board through the recall switch are good. Supply power to the control board is right at 13.4vdc. I ask my wife to begin turning on one light at a time. Every time another light comes on we drop a couple 10ths of a volt. The house battery meter is reading almost exactly what my hand held volt meter is reading. When we get about 8 lights on the meter is down to 12.95vdc and the fridge shuts off and the relay begins cycling on and immediately back off. Turn a couple of lights off and the fridge fires right up.

I swapped the fridge to propane and the exact same thing happens.

Next I fire up the coach engine. The alternator puts out very good voltage and both meters are reading in the 14.4 range on the house batteries. I begin turning on lights and fans and the furnace and every DC power user in the coach. House never drops below 14vdc and the fridge stays running like a champ. I let the coach run for about 30 minutes to give the batteries a good charge. After turning off the engine the fridge ran with lots of lights on but after about 10 minutes the house batteries got down to about 13vdc the fridge start acting up again.

I have the service manual for the fridge. The service manual says the control board needs between 10.5 and 15.4vdc to operate correctly. I have never seen the voltage at the control board drop below 12.9vdc and when it gets that low the fridge shuts off.

Has anyone ever heard of such a problem. I have already unplugged and replugged all the control voltage wiring to the board. Next I'm gonna pull the cover off the board and see if it's dusty or any other obvious problem.

All things point to a bad control board but at over $200 I want to get some assurance from you guys that it might be my problem.

Thanks for reading my long winded post. I have searched high and low on the interwebs and I cant seem to find anyone with this same problem. .

Old-Biscuit · 03-18-2023, 03:40 PM

You measured DC voltage TO the circuit board....

But what is the DC Voltage on the load side of the DC Fuse on the circuit board??

Could just be issue with the DC Fuse Holder/Clips and or solder connections (loose clip connections) on circuit board

AKIQPilot · 03-18-2023, 03:46 PM

Quote:

Originally Posted by Old-Biscuit

You measured DC voltage TO the circuit board....

But what is the DC Voltage on the load side of the DC Fuse on the circuit board??

Could just be issue with the DC Fuse Holder/Clips and or solder connections (loose clip connections) on circuit board

Yes. Only measured VDC to the board. I need to take the cover off and take some more measurements and make sure fuses and connections are clean.

Ray,IN · 03-18-2023, 03:55 PM

Just to be sure, you can temporarily bypass the Norcold black recall box to see it if might be affecting things. Just use a jumper wire(really OEM) instead of the box.
A side, note; I recommended installing a Fridge Defend unit after you solve this issue for fridge longevity.

AKIQPilot · 03-18-2023, 04:24 PM

Quote:

Originally Posted by Ray,IN

Just to be sure, you can temporarily bypass the Norcold black recall box to see it if might be affecting things. Just use a jumper wire(really OEM) instead of the box.
A side, note; I recommended installing a Fridge Defend unit after you solve this issue for fridge longevity.

And that is exactly what I just did. When I bypass the black box recall switch the fridge works properly regardless of how many DC users there are.

My problem is the recall box. When it sees 12.9vdc it momentarily trips off then back on but that causes to control board relay to drop out and then pull back in about 10 seconds later. The recall box is only tripping off for a fraction of a second. It was hard to tell because the relay on the control board makes noise and the recall box doesn't.

Are the recall boxes available to the public or do I have to have a certified Norcold tech install it?

Tell me more about the Fridge Defend unit. I will read up on it in the link you posted. Do I need the recall box and the Fridge Defend unit or does the Fridge Defend unit replace the recall box?

Ray,IN · 03-18-2023, 10:28 PM

The ARP/Fridge defend can replace the Norcold recall box. I believe it states such on the website.
At any rate, the Norcold box is sold to the public now, but if you go to an RV service center, they/Norcold replaces the box free, you pay labor.
It took me an hour to install the ARP/Fridge Defend, but I have tremors that really slowed the installation. I would never have another absorption refrigerator without an ARP unit installed.
One feature is the auto-shut off when boiler temperature rises above the setting, like parked for lunch out of level.

AKIQPilot · 03-20-2023, 12:38 PM

Just wanted to follow up on this. For most of Saturday the safety recall box worked ok as long as the coach batteries stayed above about 12.9. By mid day yesterday the box would deenergize at 13.4 volts. This basically made the fridge inoperable.

I called a couple RV techs saturday to see if anyone had one on their truck they would sell. I also called several local RV parts stores and none had one in stock.

One of the RV techs that didnt have one on his truck told me of a local RV parts store here in town that carries several in stock at all times.

9am this morning I went to the parts store and picked up a new Safety Recall box. Plugged it in and everything is working perfectly like it should.

Thanks for the help guys and hopefully this will help someone else if they encounter this problem.