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Author Topic: Norcold 982 Issues  (Read 815 times)

Donebee

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Norcold 982 Issues
« on: May 17, 2020, 09:56:57 AM »
I've been fighting this issue since last year with my Norcold 982IM fridge.

AC Heater failed on fridge last fall.

Replaced AC Heater last fall, but was still receiving C8 error, also replaced control board (Dinosaur Electronics) via warranty October 2019. Had purchased new board in April 2018.

Winter was approaching and couldn't continue diagnosing as I was storing coach for winter

Just got coach out for season, attempting to diagnose issue. AC Heater shows 45.6 ohms, technician at AC Heater vendor says it's control board.

Spoke with technician at control board vendor, he has me run a couple of tests, and then sends me yet another new control board.

Replaced control board, fridge runs fine on LP, but still shows C8 error and shuts off.

120V power at fridge outlet is good, 120V to board is good, 12V power to board is good.

AC Heater starts to heat up, but the fridge failed on AC within 90-120 seconds, showing the C8 error. (Per Norcold Service Manual - C8 = AC Heater Failed - Current out of Tolerance)

Any ideas?

Gary RV_Wizard

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Re: Norcold 982 Issues
« Reply #1 on: May 17, 2020, 11:07:06 AM »
The 900 series service manual says the heater ohms need to be between 38.3 and 42.3, so yours is out of spec at 45.6. Thus the C8 fault code is accurate.  At a guess, you have a high resistance short to ground, which is a fairly common failure mode in these heaters. If they don't just burn out, they leak a few milliamps of current to chassis ground, tripping GFCI (if applicable), triggering a fault, or maybe blowing the AC fuse on the circuit board.  It could be as simple as a single strand of wire touching the metal cartridge the heater sits in, or an internal crack in the heater rod allowing a tiny bit of current to escape.  And just to be complete, are you sure it is the correct wattage heater? 300W for this model, I think (see service manual).

http://bryantrv.com/docs2/docs/ncold900.pdf
Gary
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Home: Ocala National Forest, FL

Donebee

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Re: Norcold 982 Issues
« Reply #2 on: May 17, 2020, 11:15:01 AM »
Gary,

Thanks for the quick reply.

Yes, that's the first thing I checked this spring.

The AC Heater was replaced last fall, however I decided to double-check to ensure it was the correct part number, wattage etc.

The vendor for the part assures me that 45.6 ohms is perfectly fine, but this isn't my forte, hence the post.   

Lou Schneider

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Re: Norcold 982 Issues
« Reply #3 on: May 17, 2020, 11:34:20 AM »
Do you measure any continuity from either of the heater leads to the boiler chassis?  If there's not infinite resistance from the heater to the chassis you have a heater to chassis short.
« Last Edit: May 17, 2020, 12:29:38 PM by Lou Schneider »

Donebee

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Re: Norcold 982 Issues
« Reply #4 on: May 17, 2020, 11:57:00 AM »
Gary,

The part is stamped with 120V, 300 watts, but who knows.

I did not measure resistance between the part and case, but I did check the part while it was still fairly hot and found 3-4 ohms between the plug ends and the shaft of the rod itself. The reading zeroed out once the part cooled.

I did order another part from a separate vendor, so I'm hopeful it is the heater. Perhaps I got a failed new part?

Gary RV_Wizard

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Re: Norcold 982 Issues
« Reply #5 on: May 17, 2020, 12:16:59 PM »
Quote
The vendor for the part assures me that 45.6 ohms is perfectly fine, but this isn't my forte, hence the post.
Well, the Norcold 9xx service manual very definitively says it is NOT fine.  I don't have any more information than what is in the manual, but you can take your pick.
Gary
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Gary Brinck
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Home: Ocala National Forest, FL

Donebee

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Re: Norcold 982 Issues
« Reply #6 on: May 17, 2020, 12:20:19 PM »
Gary,

Exactly what I thought, that's why I ordered a new AC Heater from another vendor.

Just wondering if there is something else I may be missing, as I stated, this isn't my strong suit.

Lou Schneider

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Re: Norcold 982 Issues
« Reply #7 on: May 17, 2020, 12:23:46 PM »
Gary,

The part is stamped with 120V, 300 watts, but who knows.

I did not measure resistance between the part and case, but I did check the part while it was still fairly hot and found 3-4 ohms between the plug ends and the shaft of the rod itself. The reading zeroed out once the part cooled.

Since the shaft is connected to the refrigerator chassis when it's installed, that's a defective heating element with an intermittant heater to chassis short.  Most likely one of the heating wires expands enough when it's hot to touch the shaft and then retracts when it cools.   Good catch!
« Last Edit: May 17, 2020, 12:26:38 PM by Lou Schneider »

Donebee

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Re: Norcold 982 Issues
« Reply #8 on: May 17, 2020, 12:29:05 PM »
Since the shaft is connected to the refrigerator chassis when it's installed, that's a defective heating element with an intermittant heater to chassis short.  Most likely one of the heating wires expands enough when it's hot to touch the shaft and then retracts when it cools.   Good catch!

I'm hopeful it's a good catch, new part should be here this week, keeping the old fingers crossed. Mama's on me to go camping! And you know what they say; happy wife....

Donebee

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Re: Norcold 982 Issues
« Reply #9 on: May 21, 2020, 08:25:29 PM »
OK gang, I received the new AC Heater and made the replacement.

Turned on fridge and bam, two minutes later the fridge again failed with the same C8 error.

So Iíve now replaced two AC Heaters and two control boards and still cannot determine what the problem could be.

Henry J Fate

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Re: Norcold 982 Issues
« Reply #10 on: May 21, 2020, 09:55:06 PM »
I would begin to suspect the 110 volt supply to the power board. If the fridge is using a standard 110 volt electrical plug and receptacle, start by unplugging the fridge from the receptacle and plugging into a new cord from a different source. You could simply use an extension cord either directly from a plug in a power pedestal or from your home. If it is hard wired, disconnect the fridge at the junction point and run a new source to the fridge either from a power pedestal or from your home.  Test that. If you still get a C8 code, suspect any other cables or wiring that are exclusive to the 110 volt heating circuit that have been a constant with the board and element replacements. I would tend to think that you have proper control voltage (12 volts) since the fridge is working in the gas mode as it is all the same control circuit.

You may have metered good 110 volts but under load, it is possible that there may be a problem.
« Last Edit: May 21, 2020, 10:01:09 PM by Henry J Fate »

Donebee

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Re: Norcold 982 Issues
« Reply #11 on: May 21, 2020, 09:59:47 PM »
Already tried the extension cord, received the same results.

All 120V seems to check out.


Henry J Fate

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Re: Norcold 982 Issues
« Reply #12 on: May 21, 2020, 10:08:31 PM »
See if you can use a different cord and plug on the fridge side. I am not sure how the plug is connected but it may plug into the power board or possibly use wire nuts but I would eliminate that next.

Donebee

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Re: Norcold 982 Issues
« Reply #13 on: May 21, 2020, 11:01:04 PM »
Thanks, Iíll check into that tomorrow. Itís driving me crazy  :o

Henry J Fate

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Re: Norcold 982 Issues
« Reply #14 on: May 22, 2020, 05:59:51 AM »
I have looked through this thread and do not see any details of the power source/sources being used to operate the fridge. Please post details of your 110 volt power options.

What have you been using and how did you bring in a different source of 110 volts with the extension cord?

Are you using a pedestal, campground, generator, home, Inverter, solar, adapters, power monitor, surge protector, etc?
« Last Edit: May 22, 2020, 06:05:25 AM by Henry J Fate »

Donebee

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Re: Norcold 982 Issues
« Reply #15 on: May 22, 2020, 11:06:30 AM »
I draw the power from an exterior power receptacle on my residence. I run an extension cord from there to the motor home. They both have been checked and are not the culprit. I also took a clock radio, removed the 9V backup battery, unplugged the fridge and plugged it into the circuit the RV fridge is plugged into; without any issues.

Henry J Fate

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Re: Norcold 982 Issues
« Reply #16 on: May 22, 2020, 03:10:34 PM »
Do you have a generator? Have you tried to power the fridge from the generator?

Donebee

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Re: Norcold 982 Issues
« Reply #17 on: May 22, 2020, 03:41:23 PM »
Do you have a generator? Have you tried to power the fridge from the generator?
No, Iíve never tried that, but I just unhooked it from shore power, started the genny and ran the fridge, on AC power, without errors for ten minutes. It had been failing when hooked to shore power within 90-120 seconds.

Gary RV_Wizard

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Re: Norcold 982 Issues
« Reply #18 on: May 22, 2020, 05:12:06 PM »
I think we are reduced to clutching at straws here. What's different between genset and shore? Nothing in theory, but is this a motorhome with an auto transfer switch? That would mean a different relay path.   What voltage is your genset producing under load?   And I noticed you tested the fridge outlet with a tiny load, a clock radio, which is very low amp draw vs the 300W heater.  Nor do we know how sensitive that radio is to power wave form, voltage, etc. It's conceivable the clock radio works but a heavier load might not?   


You seem to have been quite thorough with your testing, but I'd go back to experimenting with the fridge plugged directly to another 120v power source, using another extension cord and a source outside the RV. Another outlet in the house than where the RV is plugged. Something is different about genset power (or it was one heck of a coincidence!). 

Last, what is the ohm reading for the latest heater? Curious to know if it is within the spec that Norcold manual says is required. Manuals have been wrong before, though.
Gary
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Gary Brinck
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Home: Ocala National Forest, FL

Donebee

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Re: Norcold 982 Issues
« Reply #19 on: May 22, 2020, 06:22:08 PM »
I think we are reduced to clutching at straws here. What's different between genset and shore? Nothing in theory, but is this a motorhome with an auto transfer switch? That would mean a different relay path.   What voltage is your genset producing under load?   And I noticed you tested the fridge outlet with a tiny load, a clock radio, which is very low amp draw vs the 300W heater.  Nor do we know how sensitive that radio is to power wave form, voltage, etc. It's conceivable the clock radio works but a heavier load might not?   


You seem to have been quite thorough with your testing, but I'd go back to experimenting with the fridge plugged directly to another 120v power source, using another extension cord and a source outside the RV. Another outlet in the house than where the RV is plugged. Something is different about genset power (or it was one heck of a coincidence!). 

Last, what is the ohm reading for the latest heater? Curious to know if it is within the spec that Norcold manual says is required. Manuals have been wrong before, though.
Yeah, Iím getting frustrated thatís for sure.

Tested the fridge, unhooked from shore power with a separate outlet and cord and same error.

Yes, the motorhome has an auto transfer switch.

Tested the fridge on shore power, and the AC Heater shows a steady draw at 119.3 to 119.4V. Testing on the genny, with shore power disconnected shows a little higher, 120.4 to 121.4.

Ohm of the new AC Heater right out of the bag showed 45.8, higher than what the specs show.

When I used the clock radio I was simply testing the 120V outlet, to see if it was losing power as suggested elsewhere.

Gary RV_Wizard

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Re: Norcold 982 Issues
« Reply #20 on: May 23, 2020, 10:00:22 AM »
Quote
When I used the clock radio I was simply testing the 120V outlet, to see if it was losing power as suggested elsewhere.
Yeah, I got that, but you clearly are NOT losing power. The C8 error is not a power loss code. The fridge controller is monitoring current and deciding to shut the heater off due to an out-of-spec condition (too much {or too little?} current flow). Wish we knew more about how they determine that, but probably no hope of learning that.
I was thinking you might have a weak outlet for the fridge and it got flaky under load, but if it performs OK with the genset I think that can be ruled out.


The slightly higher voltage of the generator would have a small effect on the current and/or wattage, but I'll yield to the electrical engineers to assess the importance of that.  However, if it always works ok on genset power but always gets the C8 error on shore power, that tells us something. We just need to figure out what is different.
« Last Edit: May 23, 2020, 10:15:48 AM by Gary RV_Wizard »
Gary
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Donebee

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Re: Norcold 982 Issues
« Reply #21 on: May 23, 2020, 10:03:10 PM »
So, I decided to check an entirely new power source. Took motorhome to my sonís house (brand new electrical service) and....same error.

Had son test AC Heater on both genny and shore power, 2.5 amps, 120 volts on both.


Henry J Fate

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Re: Norcold 982 Issues
« Reply #22 on: May 24, 2020, 07:18:00 AM »
It is going from crazy to worse. It would be hard to believe that you have been unlucky enough to have purchased several faulty parts but at this point, you really cannot rule out anything.

Have you replaced the power plug and cord yet? That cord has been a common thread in all your repair attempts. If you replace that and still get the 38 code, guess you could consider the control panel on the front  of the fridge. I wouldn't know exactly how that board could cause the 38 code but it is another part that has been common to all of your repairs.
« Last Edit: May 24, 2020, 07:20:38 AM by Henry J Fate »

Gary RV_Wizard

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Re: Norcold 982 Issues
« Reply #23 on: May 24, 2020, 07:24:03 AM »
Power cord?   It's the same fridge power cord when using the generator and no error then. Did you mean the entire shore power cord?
Gary
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Gary Brinck
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Home: Ocala National Forest, FL

Donebee

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Re: Norcold 982 Issues
« Reply #24 on: May 24, 2020, 08:59:46 AM »
Power cord?   It's the same fridge power cord when using the generator and no error then. Did you mean the entire shore power cord?

Agreed, if he was referring to the power cord for the fridge, it, as you stated, works off the genny but not off shore power.

I cannot fathom I received two bad AC Heaters and two bad control boards.

It almost has to be something in the design of the board that is sensing that the AC Heater is out of tolerance. Both parts show around 45.6 ohms, which is higher than the specs show for that part. My son tested with his Fluke meter when on genny and one his home's shore power. Both tests show 2.5 amps and 120V when the fridge is running.

The techs at Dinosaur Electronics are supposed to be calling me back, they've been pretty helpful to this point.   

Henry J Fate

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Re: Norcold 982 Issues
« Reply #25 on: May 24, 2020, 06:18:45 PM »
The cord which plugs into the ac outlet from the fridge. I believe it is the fridge cord that he unplugged from the coach ac receptacle and then plugged it into the extension cord for one of his tests. That kwould have bypassed all of the internal coach wiring but he would be still using the same cord from the fridge.

If the fridge has that cord on it, that cord has been common to every new board, heater and test. By pass that cord.

If it does not have that ac cord, I would suspect the ac wiring from the fridge to the ac supply. I thought it was a standard 15 amp plug but maybe it is hard wired. Bypass what ever is being used.


Maybe I read the post wrong but I thought the fridge failed on generator power but did last longer? Sorry I am out on the road I may have not read things properly.



« Last Edit: May 24, 2020, 06:26:05 PM by Henry J Fate »

Henry J Fate

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Re: Norcold 982 Issues
« Reply #26 on: May 24, 2020, 06:34:33 PM »
Just looked back. I think you said the generator ran the fridge for 10 minutes without any problem. I would run it for more than that to be sure. At least 1/2 hour. An hour would be better and keep watch of things. If you think it is fine on generator power, we then have a new clue. Maybe a flaky transfer switch that is not fully switching. Start looking at other things but be sure the fridge is working on generstor power for an extended period.

Donebee

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Re: Norcold 982 Issues
« Reply #27 on: May 25, 2020, 08:55:43 AM »
Just looked back. I think you said the generator ran the fridge for 10 minutes without any problem. I would run it for more than that to be sure. At least 1/2 hour. An hour would be better and keep watch of things. If you think it is fine on generator power, we then have a new clue. Maybe a flaky transfer switch that is not fully switching. Start looking at other things but be sure the fridge is working on generstor power for an extended period.

The fridge ran fine on the genny for ten minutes. I shut it off after that as the fridge had failed on shore power within 2-3 minutes when running on shore power. Tested fridge on separate circuit at home, and also check at my son's house (brand new electrical service) and received same C8 error. My son (electrician) checked AC Heater on fridge at his house and it checks at 2.5 amps/120V on both genny and shore power. Both AC Heaters are Norcold brand, both ohm at 45.6, which is above specs posted by Norcold (38-42).

Gary RV_Wizard

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Re: Norcold 982 Issues
« Reply #28 on: May 25, 2020, 09:32:47 AM »
Definitely re-test using the generator because it could well be a critical clue.  If you can, re-test both directly using an extension cord and via the normal RV internal wiring. If the fridge works consistently on generator but fails consistently on shore power, you've come along way toward isolating the problem and can focus on  "what's different" between those two. The shore cord and ATS are obvious, but you can eliminate that by direct plugging the fridge power cord to either source.   Plugging direct to a generator is easy for a portable, but not so much for a motorhome built-in genset.
Gary
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Gary Brinck
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Home: Ocala National Forest, FL

Donebee

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Re: Norcold 982 Issues
« Reply #29 on: May 26, 2020, 02:35:25 PM »
Definitely re-test using the generator because it could well be a critical clue.  If you can, re-test both directly using an extension cord and via the normal RV internal wiring. If the fridge works consistently on generator but fails consistently on shore power, you've come along way toward isolating the problem and can focus on  "what's different" between those two. The shore cord and ATS are obvious, but you can eliminate that by direct plugging the fridge power cord to either source.   Plugging direct to a generator is easy for a portable, but not so much for a motorhome built-in genset.
Unplugged shore power and ran the fridge on the genny for a solid hour. Fridge cooling properly, no errors. Switched off genny and ran on LP, no issues. Reconnected shore power, nearly immediate C8 error. I had previously tested a different shore power at my sonís house (brand new electrical service) and had same C8 error on his AC power as well.