Norcold Fridge Issues

[Donebee]

Norcold 982 fridge issue. I am receiving a C8 error, “AC Heater Failed for Current Out of Tolerance” per the Norcold Service Manual.

I’ve replaced the AC Heater twice, and the main control board twice.

120V AC is good at board and at plug-in.
12V DV is good.

Any ideas?

[Donebee]

Old-Biscuit wrote:

dougrainer wrote:

Old-Biscuit wrote:
Dinosaur Electronics Circuit Boards are higher quality then Norcold OEM board

Dino Board is NOT your issue

Runs fine on Generator but problem on Shore Power

Shore Power Supply is your issue.......not the heater element/Dino Circuit Board

They are higher quality, but CAN Have a Failure. NOBODY makes a 100% perfect product. Doug

"YOUR problem is simple, you used a NON Norcold control board."
:h :R

That may very well be true Doug, perhaps you can point me to where to buy a Norcold control board?

[Donebee]

Old-Biscuit wrote:
Dinosaur Electronics Circuit Boards are higher quality then Norcold OEM board

Dino Board is NOT your issue

Runs fine on Generator but problem on Shore Power

Shore Power Supply is your issue.......not the heater element/Dino Circuit Board

Took motorhome to my sons’s house to verify problem wasn’t with my home/shore power. Brand new grounded electrical service, still shows same error.

[Old-Biscuit]

dougrainer wrote:

Old-Biscuit wrote:
Dinosaur Electronics Circuit Boards are higher quality then Norcold OEM board

Dino Board is NOT your issue

Runs fine on Generator but problem on Shore Power

Shore Power Supply is your issue.......not the heater element/Dino Circuit Board

They are higher quality, but CAN Have a Failure. NOBODY makes a 100% perfect product. Doug

"YOUR problem is simple, you used a NON Norcold control board."
:h :R

[dougrainer]

Old-Biscuit wrote:
Dinosaur Electronics Circuit Boards are higher quality then Norcold OEM board

Dino Board is NOT your issue

Runs fine on Generator but problem on Shore Power

Shore Power Supply is your issue.......not the heater element/Dino Circuit Board

They are higher quality, but CAN Have a Failure. NOBODY makes a 100% perfect product. Doug

[Old-Biscuit]

Dinosaur Electronics Circuit Boards are higher quality then Norcold OEM board

Dino Board is NOT your issue

Runs fine on Generator but problem on Shore Power

Shore Power Supply is your issue.......not the heater element/Dino Circuit Board

[dougrainer]

Donebee wrote:

GordonThree wrote:
So you have replaced both the heating element and the controller board?

Yes, and I just tried running the fridge on the genny, unhooked from shore power and it seemed to run without errors. I ran it for about ten minutes without error, when on shore power it was failing within 2-3 minutes.

You need to check the Shore Power voltage and frequency. Doug

PS, This is something I have NEVER seen or heard about in 41 years as a RV tech. I have worked on thousands of RV refers. YOUR problem is simple, you used a NON Norcold control board. You also need to contac Dino for help. If at our shop and it DID show the error on our shop power, then it would be obvious the Dino board is the problem. To verify I would install the correct Norcold OEM part.

[Donebee]

GordonThree wrote:
So you have replaced both the heating element and the controller board?

Yes, and I just tried running the fridge on the genny, unhooked from shore power and it seemed to run without errors. I ran it for about ten minutes without error, when on shore power it was failing within 2-3 minutes.

[GordonThree]

So you have replaced both the heating element and the controller board?

[Donebee]

Both AC Heaters were Norcold parts, correct part number, wattage, etc. Both control boards were from Dinosaur Electronics. Both AC Heaters were checked and were within specs while still failing.

[Old-Biscuit]

Norcold 982 uses a 300W element and should measure 38 - 42 Ohms

See Section 16 pg 18
Norcold 900/9100 Series Service Manual

[GordonThree]

Dang computers!

I haven't had to troubleshoot this, but it sounds like the control board measures the current used by the AC heating element, and what it's reading doesn't match spec. Could be a safety feature, could be a tool to prevent you from using 3rd party parts.

When you replaced the heater, did you replace with a genuine part? Where did you order from, maybe you received a counterfeit part?

Does the service manual publish how many OHMS the a good heating element should measure, or at least how many watts the heating element is rated for (then you can calculate the ohms)?

This will give you a number to look for that a regular multi-meter can tell you. IF the number you MEASURE matches the number published / calculated, then likely the part of the control board that measures current is faulty.

EDIT: found this link that explains what to measure and how to calculate:

https://www.arprv.com/norcold-ac-heater.php