Norcold 982 Issues

[Gary RV_Wizard]

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.

 

[Donebee]

So, I decided to check an entirely new power source. Took motorhome to my son?s 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]

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.

 

[Gary RV_Wizard]

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?

 

[Donebee]

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]

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.

 

[Henry J Fate]

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]

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]

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.

 

[Donebee]

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 son?s house (brand new electrical service) and had same C8 error on his AC power as well.

 

[Gary RV_Wizard]

Reconnected shore power, nearly immediate C8 error. I had previously tested a different shore power at my son?s house (brand new electrical service) and had same C8 error on his AC power as well.

Assuming the genset powered the fridge in the normal fashion, then most all of the coach wiring must be ok (it used the same wiring from the Auto-transfer switch onward). That would say the problem has to be  in either the ATS or the shore cord.  However, you previously stated the C8 error occurred when the fridge was plugged directly to an external extension cord.  I don't see how both of those things could be true at the same time. You seem to be quite rigorous in your testing but there has to be something common to those failing tests that is causing the C8 error.

 

[Lou Schneider]

A long shot, but have you checked polarity at the refrigerator socket on both generator and shore power? 

Plug in one of those 3 light testers or take voltage measurements to ground at the outlet to be sure  both power sources deliver hot and neutral to the correct pins and both have intact grounds.

I'm guessing one or the other has either reversed polarity or a missing ground that's confusing the circuit board.

 

[Henry J Fate]

Grabbing at another straw here, do you have an inverter wired to the transfer switch?? Or any inverter being used?

One other thought... The transfer switch may respond slightly better to the generator power. The path of ac power should be much shorter to the distribution panel resulting in less of a voltage drop and the generator would only be powering circuits in the rv which is not the case when connected to shore power. I have seen voltage variances of 10 volts on shore power......something else to think about.

 

[Henry J Fate]

Polarity or a bad ground is a good thought however I would suspect the cord on the fridge rather than the receptacle. An extension cord was used to power the fridge directly to it's power cord which bypassed the receptacle and all internal rv wiring except for the fridge power cord which is still on my suspect list.

 

[fcabrerausa]

I was having the same issue and same symptoms, I replaced the element and no joy. In my case disconnecting the individual 120V leads from the power cord to the ice maker up top fixed the power issue.