Norcold frig not cooling well?

[lhemrick]

I have a Norcold 8662 frig that is cooling but not well. The heating unit is working and it maintains a constant temp. The frig is holding at 60 degress and the freezer at 25. I have already cleaned all the connections on the circuit boards. I have also had it out and turned upside down to mix it. What could be the issue?

Thanks!

[Carolaow]

Are you in a real hot area right now? Mine was having a terrible time while in Texas this summer. I started using a fan to circulate the air in the compartment behind the frig and that helped a great deal. While traveling, there was no problem because the air circulated better while underway. Other than that, no idea!

[Kirk W]

First let me welcome you to the Escapee forums! We have a lot of experience here so someone should be able to help you with most problems.

 

On your particular refrigerator, you can get a copy of the service manual from Bryant RV's website. To get a copy, just click on this link and then download and save it in .pdf format.

 

One thing that I'm wondering is how old the refrigerator is? The symptom that you are describing sounds like you may have begun to loose refrigerant from the cooling unit. Check for any odor of ammonia in the cool box area or inside of the rear (outside) access panel and also in the back look for any signs of a yellow powder of sludge. Any of those indicate some loss of refrigerant and that sore of problem usually means that the cooling unit has begun to leak and will likely get worse until it completely fails. You should also try operating on both 120V and on propane to see if either one works better than the other.

 

The RV refrigerator always cools the freezer section first and any remaining refrigerant then enters the cooling coils of the chill box section to complete the useful absorption of heat. The fact that your freezer is staying below freezing, but the chill box isn't cooling much at all seems to indicate that you don't have enough refrigerant to cool both. Monitor the boiler temperature to determine if it is in constant cool effort and if so, this is definitely a problem of too little cooling capacity for one reason or another. If the boiler is not getting to a high enough temperature, that too wold cause some loss of cooling capacity. As suggested, you can enhance the ability of the cooling unit at least to some degree by adding additional air flow through the back so the addition of a small fan blowing up through the back is a good thing to try. It may even get things low enough to be at a safe temperature for a time, but if it has worked properly in the past without the added ventilation, then that as a fix is probably temporary.

 

If you have had some insulation come loose in the upper section of the refrigerator, it may be blocking the air movement and that could cause a problem like you have. A very dirty flue with bug nests and such could also cause the problem so you may want to check that as well. If you have access to a good shop vac you may want to apply the suction of it to the lower end of the burner area to see what you can draw out of the flue and burner.

 

The service manual that I gave you the link for has a trouble shooting guide that starts on page 15. You will need a reasonably good meter to do the diagnostics called for in those pages. When you begin to do that series of checks, keep us posted on what you find as we may be able to help you in determining just what the problem is.

[oldjohnt]

I'm not smart enough to get into ammonia levels like Kirk was talking about, I leave that to the fridge tech not to far from here. In the event it worked better on electric then gas (does it, if so flame may be to low) I would inspect and clean the burner assembly and flu area to clean any obstructions. I use a combination of my air compressors blow gun plus a shop vac to clean all the soot and carbon and cob webs THAT CAN REALLY HELP IN CASES when gas operation isn't cooling like electric. Ditto on what Kirk said about a good meter, I found out a few tenths of a volt can make or break proper operation. I placed a small muffin fan in rear compartment to help blow air up past the coils and out the top vent but I cant tell it made any difference. What helps mine is its on the RV side that's under the awning versus hot sun bearing down on it. WHAT ALSO HELPS KEEP MINE WORKING BETTER is I placed small twin muffin fans on the upper inner heat exchanger fins which keeps them frost free.

 

Keep "cool"

 

John T

[nana25k]

Are their fans last cared on the top of your refer that help exhaust\vent the hot air. Check them to see if they are working. This was certainly one of our situations

[TXiceman]

The ammonia concentration on an RV frig is VERY critical and not something that only a very few techs are capable of working with. The unit is sealed and ammonia level is not able to be checked.

 

Look for any leaks by looking for any spots of a yellow or an orange looking residue. If it is leaking....it is history and should not be operated at all.

 

If no leaks, make sure you have external fans to help the circulation and add an internal fan as well. Make sure you do not park with the south and west sun on the wall with the frig.

 

Ken

[lhemrick]

I have purchased a new thermister. I can't see or find where it plugs in to the unit. I have watched a Youtube video where one was replaced and this gentleman just cut the wire inside the frig and connected to new one to it. He said it didn't matter which wire went where. Is that true?

I have a Norcold 8662 made in the middle 80's.

Thanks!

[Bill Joyce]

Check the door seals. You close the door on a dollar bill and if it pulls out, that is your problem spot. http://fergizmo.blogspot.com/2015/08/smoky-washington-idaho-dalton-gardens.html shows you how to fix the seal with a hair dryer.

[Kirk W]

I have purchased a new thermister. I can't see or find where it plugs in to the unit. I have watched a Youtube video where one was replaced and this gentleman just cut the wire inside the frig and connected to new one to it. He said it didn't matter which wire went where. Is that true?

I have a Norcold 8662 made in the middle 80's.

The thermistor connection is a two lead plug that connects to the main circuit board in the back of the refrigerator, but the video is correct that it is more easily replaced by cutting the wires and also that the lead connections do not matter which is which. A thermistor is simply a resistor that changes in resistance as the temperature changes and at a fixed rate. The only problem with cutting the wires to install a new one is in making sure that it is insulated and moisture tight.

 

I wish you luck in the part change solving the problems you are having. Keep in mind that with a refrigerator that is about 30 years old, it is questionable to spend a great deal on repairs.

[DaMechanic]

Look up dometics website. There is a MAJOR recall, and sometimes they can explode. DON'T use propane till you talk to them.

[chirakawa]

Look up dometics website. There is a MAJOR recall, and sometimes they can explode. DON'T use propane till you talk to them.

 

Would you be kind enough to furnish a link to this recall please. I was unable to find any recalls, MAJOR or minor, for the Dometic Model 8662.

 

Here is the only recall I could find http://67.238.126.140/recall.php

[DaMechanic]

okay, they totally changed the website in the last month. The one I saw had the full range of everything. Before, it said eactly what would happen and why. Honestly, doing us this way is total bull. Here is the gist of what it said as far as I can remember. These units can overheat when in use due to a manufacturing defect. Due to thism if the system is corroded it can burst. Overheated ammonia breaks down into hydrogen gas. Here's the cincher though. ALL THEY ARE DOING IS INSTALLING A HALON FIRE EXTINGUISHER. They are not repairing the manufacturing issue, they just want to keep it from leveling your trailer. They don't care if it breaks or noi, they just want to keep from being sued for wrongful death. I've read of this failure happening in six months of use. I'll never buy a dometic product again.

 

EDIT: Forgot this part. If your unit is not listed, it's because it was already installed at the factory. It may be too late, your system already burst, and the halon went off to keep your trailer from burning to the ground.

[Iamhopeful]

Norcold RV Refrigerator Model #1200 LRIM SN# 1100720F

 

Works fine on 12vlts DC only

Does not work on AC

Monitor reads: AC LO when in the AC mode

I have checked the 12 vls and 120 vls circuits both are reading correct voltages

 

I disconnected the 120 vlt leads to the heating elements and read continuity

 

Readings are: .06 ohms on the 20 K ohms scale. So heaters are not open

 

However I did not get 120 vlts leading to the heating elements

 

Could the monitor control be the problem?

 

I appreciate all the help I can get

 

Harold

[dontrump]

 

I have purchased a new thermister. I can't see or find where it plugs in to the unit. I have watched a Youtube video where one was replaced and this gentleman just cut the wire inside the frig and connected to new one to it. He said it didn't matter which wire went where. Is that true?

I have a Norcold 8662 made in the middle 80's.

Thanks!

 

The thermistor is most likely the least of your problems.When a thermistor goes bad it usually cause food to freeze . Based on your fridge,s age I will say more than 99% likely your fridge is toast and time to replace

[Kirk W]

Norcold RV Refrigerator Model #1200 LRIM SN# 1100720F

 

Works fine on 12vlts DC only

Does not work on AC

Monitor reads: AC LO when in the AC mode

I have checked the 12 vls and 120 vls circuits both are reading correct voltages

 

I disconnected the 120 vlt leads to the heating elements and read continuity

 

Readings are: .06 ohms on the 20 K ohms scale. So heaters are not open

 

However I did not get 120 vlts leading to the heating elements

 

Could the monitor control be the problem?

 

I appreciate all the help I can get

 

Harold

By saying it works on 12V only, do you mean that you are using propane or do you have a 3 way refrigerator? The resistance of a good heating element in your refrigerator should read somewhere between 50Ω abd 70Ω so if your reading is accurate, yours is of far too low a value, but you need to use a lower range to accurately read the value. Heaters often fail by breaking and so have an extreme high resistance, but they can also fail by shorting so that they don't generate any heat.

 

Have you checked the fuses on the main circuit board? There are usually two of them, a 3A fuse for the 12V control circuitry and a 5A fuse in the 120V supply to the heaters. All controls for the refrigerator are powered by 12V-dc power no matter what energy source you are using to heat the refrigerant boiler.

[wildmandmc]

Look up dometics website. There is a MAJOR recall, and sometimes they can explode. DON'T use propane till you talk to them.

thanks bud, as i was in future going to post something about that, mine had recall done, an they prob disconected the propane from frig.

(not trying to hijack this thread). reason why mine will not operate on propane.

[Wrknrvr]

The 1200 has a habit of the holder for the 120 vac fuse to corrode. Then it will not pass 120vac current. Sometimes it may pass 120 vac but will not pass the correct amperage.

You need an amp meter to test correctly.

If you are going to work on the fuse holder remove the 120vac power, turn off the fridge and be really careful with the holder as it may have gotten hot and lost the spring action to hold the fuse in place.

If I remember it is normally the right side that is the problem.

It may have burned off the back of the board.

 

 

Be Safe, Vern

[Iamhopeful]

Thank you for your time. Yes right now it is only working on gas. No it is not a 3 ways refrigerator. Drs appt are keeping me away from working on it today. I will contact you and report tomorrow

 

Harold

[dontrump]

Norcold RV Refrigerator Model #1200 LRIM SN# 1100720F

 

Works fine on 12vlts DC only

Does not work on AC

Monitor reads: AC LO when in the AC mode

I have checked the 12 vls and 120 vls circuits both are reading correct voltages

 

I disconnected the 120 vlt leads to the heating elements and read continuity

 

Readings are: .06 ohms on the 20 K ohms scale. So heaters are not open

 

However I did not get 120 vlts leading to the heating elements

 

Could the monitor control be the problem?

 

I appreciate all the help I can get

 

Harold

1200 fridges do not cool on 12 volts they cool using 120V or LPG 12V DC is required to run the electronics on either LPG or 120V so when u say cooling ok on 12V your mistaken and its on LPG seeing as U claim your heating elements receive 120V most likely senereo is heating elements are bad

[rvtamer]

 

I have a Norcold 8662 frig that is cooling but not well. The heating unit is working and it maintains a constant temp. The frig is holding at 60 degress and the freezer at 25. I have already cleaned all the connections on the circuit boards. I have also had it out and turned upside down to mix it. What could be the issue?

Thanks!

 

Hello Ihemrick and welcome to Escapees,

 

I have worked on a few of these units in the past and would like to ask some questions to see if I could be of assistance.

 

1) Another poster suggested that you look for a yellow substance or If you smelled a strong odor of ammonia . Have you noticed either one of these ? This would indicated a cooling unit failure.

2) Before you removed the refer out to "burp " it, did you ever hear any " crackling " sounds coming from the refrigerator ? Have you since after you removed the refer and reinstalled it ? This crackling noise indicates lose of the cooling solution and will never cool as designed.

3) When you removed the refer, did you or anyone check or remove the spiral baffle ? It is critical that it is still present doing its job.

4) Is the thermistor installed on the 5th fin on the right side. To get a little more cooling ( couple degrees usually ) , you can move it up on the fin towards the top.

5) Have you checked to see if the interior light stays on when the door is closed. This can heat up the box interior.

6) Check the back of the refer where the thermistor wires go into the rear of the refer . This must have sealant applied to prevent warm air intrusion. This also applies to the condensation line.

7) When you checked the box temperature, did you check the surrounding air temp or use another means ? When you open the box, it loses several degrees each time before you can register a temp. I would suggest placing a glass of water in the lower box. When you open the lower box door, the water will retain the temperature much longer than the air, and you get a better idea of the box temperature.

8) Another poster stated to check the door seals. I agree.

9) Have you had the vent cap off since or before you removed the refer to burp it ? You need to check for protruding insulation that might be covering any part of the top of the coils. Also check to see if any insects have built a nest that blocks air flow toward the vent cap.

 

What concerns me most is your recorded freezer temp of 25 degrees. That is way too high for that part of the cooling unit system. It definitely indicates a problem ....................tim

[Kirk W]

Thank you for your time. Yes right now it is only working on gas. No it is not a 3 ways refrigerator.

I'd start by checking the 120V fuse. Let us know when you get the chance. Remove the fuse and check it with a meter as just looking doesn't always prove to be accurate. To make sure that the fuse has a good connection, once it is proven good by showing 0 ohms through it with an ohm meter, then turn it back to 120V with the fuse in and measure the voltage across the two ends of the fuse. Put the probes on the base of the fuse holder and not the fuse because that will make sure that it is making a good connection. It should read 0V if the fuse and the contact are both good.

 

Hello Ihemrick and welcome to Escapees,

 

What concerns me most is your recorded freezer temp of 25 degrees. That is way too high for that part of the cooling unit system. It definitely indicates a problem ....................tim

He posted his problem on Aug. 24 and has not returned since Aug. 29. Some of us are responding to Harold, who has the current post.

[dontrump]

If the 120V fuse was bad how would he have 120V going to heating elements?

[Iamhopeful]

Thanks for your input. You are correct my message had a type O. I meant to board had 12 vlt DC and 120 vlts AC The refrigerator works on LP gas but not on AC The monitor inside keeps on flashing AC LO

 

120 volts in at fuse in and out (5 amp fuse is good)

Resistance of 120 vlts heating element 69 ohms each

After removing board and inspecting , there are signs of overheating.

Actually 5 amp fuse was hot when I removed it prior to removing the board

Nothing was actually burned open but showing caramel colored around the resistors above the fuse (5 amps)

After re-installing the board I left the leads disconnected that feed the heating elements and read no voltage at the terminals

I read the voltage at the lower end of resistor R24 and read 134 volts and at the top only 31.7 volts

 

I ordered a new board, when I have it installed I will inform you of the results.

 

Harold

[Iamhopeful]

To bring everyone up to date in reference to My Norcold refrigerator cooling problems: First all, There was a type " O " in

explaining. The problem. I didn't mean it run on 12 volts DC but not on 120vac. It has to have 12 VDC for the controls to work so it worked fine on LP Gas. but not on 120 VAC.I first checked the voltages all was correct. The board showed some dis-coloring on the back side of the 120 AC fuse and resistors, but nothing was .actually burned open. After checking the circuits to make sure that there were no shorts. I determined the board was defective.

 

I found the best prices on line. I bought a Dinosaur board. For much less than the Dealers prices, And I Installed myself. I hope this information will help others. This Board will replace several different boards.The model I bought was #621xx. The number of the board most RV's should be printer on their board.

 

Additional information:Dinosaur Electronics Phone # is:541-9944344.

 

HP Electric Retired Electrical Tech

[Kirk W]

Thanks for the update. Also for letting us know that you are a retired service tech. as it helps to know a little about the background of the one we are advising. I too may my living in that same field for 40 years so we probably share a lot of background history.

I found the best prices on line. I bought a Dinosaur board. For much less than the Dealers prices, And I Installed myself. I hope this information will help others. This Board will replace several different boards.The model I bought was #621xx. The number of the board most RV's should be printer on their board.

 

HP Electric Retired Electrical Tech

On the Dinosaur Electronics products, I am a strong supporter of them as I have used their boards in several appliances in RVs, both my own and those of friends. The circuit boards that they make are guaranteed for 3 years, while those of the OEM are only 1 year at most. In addition, I have found their products to be of better quality and design than the OEM boards and they cost less. The only negative that I am aware of is that sometimes it requires some modifications in order to install the Dinosaur circuit boards but those are usually minor.