clicking sound from Norcold control module

[Heating man]

The refrigerator is working OK but I worry about this clicking. It sounds like a relay clicking in the control module. It does it constantly. Anyone had this problem and what was the solution.

[Old-Biscuit]

Model would be helpful


Possibly the electric heater element relay.


Would have to remove circuit board cover......plug all leads/wires back in
Turn on and listen closely to where clicking is coming from

[Dezertbum]

Originally Posted by Old-Biscuit

Model would be helpful


Possibly the electric heater element relay.


Would have to remove circuit board cover......plug all leads/wires back in
Turn on and listen closely to where clicking is coming from

Hi Biscuit, I know, old thread here. I have a Norcold 1200 (2001) and I have a newer (three Years ago) dinosaur circuit board in it. When it gets cold, it seems to have a constant relay clicking every few seconds in the board. Is this normal operation? Is it just trying to maintain the temperature? Seems to be clicking quite often.



Thanks, Jeff

[Old-Biscuit]

Originally Posted by Dezertbum

Hi Biscuit, I know, old thread here. I have a Norcold 1200 (2001) and I have a newer (three Years ago) dinosaur circuit board in it. When it gets cold, it seems to have a constant relay clicking every few seconds in the board. Is this normal operation? Is it just trying to maintain the temperature? Seems to be clicking quite often.



Thanks, Jeff

There are several relays on circuit board
One or Two for the AC Heater element leads (serial # dependent)
One for Flapper heater
One for Gas Valve solenoids

So you would need to ID which one is clicking......
Should be closed/open not clicking ---that will destroy contacts in the relay
*Could be failing component or relay

[K7JV]

Just a quick thought for you. We had that on our 2021 Esteem and it turned out to be caused by low voltage on the supply to the refrigerator. I posted my troubleshooting and fix on IRV2, with the last post within the last couple of weeks. It turns out another Esteem owner had the same problem. Something Entegra did in the wiring process resulted in a higher than normal resistance in the circuit from the fuse panel to the refrigerator.

To check out this possibility, see if you can put a voltmeter on the 12V connection to your refrigerator. I used a screw on the back of the refrigerator for the ground connection and probed the terminal where the 12V conductor was connected to the refrigerator.

Depending on your meter, if your problem is similar to ours, you will see it go between maybe 13+ volts (assuming you are plugged into shore power or have solar charging at the time), and then maybe 11- volts, alternating with the clicks.

If that is what you find, you can either find the point where the higher resistance has developed, or you can run a new 12V supply conductor to the unit.

Let us know what you find. Cheers and good luck to you!

[Fridge Defend]

Originally Posted by K7JV

Just a quick thought for you. We had that on our 2021 Esteem and it turned out to be caused by low voltage on the supply to the refrigerator. I posted my troubleshooting and fix on IRV2, with the last post within the last couple of weeks. It turns out another Esteem owner had the same problem. Something Entegra did in the wiring process resulted in a higher than normal resistance in the circuit from the fuse panel to the refrigerator.

To check out this possibility, see if you can put a voltmeter on the 12V connection to your refrigerator. I used a screw on the back of the refrigerator for the ground connection and probed the terminal where the 12V conductor was connected to the refrigerator.

Depending on your meter, if your problem is similar to ours, you will see it go between maybe 13+ volts (assuming you are plugged into shore power or have solar charging at the time), and then maybe 11- volts, alternating with the clicks.

If that is what you find, you can either find the point where the higher resistance has developed, or you can run a new 12V supply conductor to the unit.

Let us know what you find. Cheers and good luck to you!

This is good troubleshooting information!

I did not see the make and model of the fridge from the owner, and I am rushing to get to a meeting.

All absorption refrigerator controllers have mechanical relays on the controller. Also there are relays and valves that click and make noise.

Put your finger on each of the devices to see if you can determine what is clicking? Once we know, it will be easier to determine the why?

FYI: If your heat source is cycling on and off, this will overheat the cooling unit boiler, so this problem should be fixed ASAP to avoid damage to the fridge.

Hope this helps

[K7JV]

Just adding a wee bit more to my post above. In our Esteem, and the other gentleman's Esteem, it turned out the clicking problem actually had nothing to do with the Norcold refrigerator. The refrigerator was simply responding as it would to being fed too low of a power supply voltage.

What was happening was that when whichever relay it was in the refrigerator opened, it took over 2 amps of load off of the power supply conductors. As soon as the voltage recovered, the relay re-energized, thus putting the approximately 2 amp load back on. As soon as the load picked up, the higher current resulted in the return of the voltage drop, and the relay opened once again. It was a continuous cycle of operations. It literally sounded like a large mechanical clock, making a "tick" "tock" sound, at about a one second interval.

The circuit feeding the refrigerator tested out to have about 0.6 ohms of resistance. That's not much, but at two plus amperes, that resulted in most of a couple of volts of drop in the supply at the refrigerator. New conductors installed direct from the Norcold to the fuse block and and all is good. Sure wish I knew what Entegra did to result in the high impedance in the feed line, but it appears ours wasn't the only similar coach that had the problem. Too small of wire for a portion of the run? Maybe? That fuse fed the refrigerator, the propane detector, the coach radio system and the control circuit for the slide-outs. Interesting.

[Dezertbum]

Originally Posted by K7JV

Just adding a wee bit more to my post above. In our Esteem, and the other gentleman's Esteem, it turned out the clicking problem actually had nothing to do with the Norcold refrigerator. The refrigerator was simply responding as it would to being fed too low of a power supply voltage.

What was happening was that when whichever relay it was in the refrigerator opened, it took over 2 amps of load off of the power supply conductors. As soon as the voltage recovered, the relay re-energized, thus putting the approximately 2 amp load back on. As soon as the load picked up, the higher current resulted in the return of the voltage drop, and the relay opened once again. It was a continuous cycle of operations. It literally sounded like a large mechanical clock, making a "tick" "tock" sound, at about a one second interval.

The circuit feeding the refrigerator tested out to have about 0.6 ohms of resistance. That's not much, but at two plus amperes, that resulted in most of a couple of volts of drop in the supply at the refrigerator. New conductors installed direct from the Norcold to the fuse block and and all is good. Sure wish I knew what Entegra did to result in the high impedance in the feed line, but it appears ours wasn't the only similar coach that had the problem. Too small of wire for a portion of the run? Maybe? That fuse fed the refrigerator, the propane detector, the coach radio system and the control circuit for the slide-outs. Interesting.

Thank you all for your replies. I will check that out.

[Fridge Defend]

Originally Posted by K7JV

Just adding a wee bit more to my post above. In our Esteem, and the other gentleman's Esteem, it turned out the clicking problem actually had nothing to do with the Norcold refrigerator. The refrigerator was simply responding as it would to being fed too low of a power supply voltage.

What was happening was that when whichever relay it was in the refrigerator opened, it took over 2 amps of load off of the power supply conductors. As soon as the voltage recovered, the relay re-energized, thus putting the approximately 2 amp load back on. As soon as the load picked up, the higher current resulted in the return of the voltage drop, and the relay opened once again. It was a continuous cycle of operations. It literally sounded like a large mechanical clock, making a "tick" "tock" sound, at about a one second interval.

The circuit feeding the refrigerator tested out to have about 0.6 ohms of resistance. That's not much, but at two plus amperes, that resulted in most of a couple of volts of drop in the supply at the refrigerator. New conductors installed direct from the Norcold to the fuse block and and all is good. Sure wish I knew what Entegra did to result in the high impedance in the feed line, but it appears ours wasn't the only similar coach that had the problem. Too small of wire for a portion of the run? Maybe? That fuse fed the refrigerator, the propane detector, the coach radio system and the control circuit for the slide-outs. Interesting.

Boy oh Boy! You tripped my trigger

First the positive, glad you found the issue, this is why we put a voltage read out on our product. The first question is to have someone read the voltage and/or memory to see the min/max voltage supplied to the fridge.

Next the trigger, "fuse fed the refrigerator, the propane detector, the coach radio system and the control circuit for the slide-outs".

This is, from an electrical engineering power distribution standpoint not responsible at all. Your fridge draws about 0.5A typically, and the entire fridge electrical distribution should be on a 5A max circuit protection circuit.

The "propane detector" is a safety device, just like our product. Anyone that does not promote safety is, well you know The safety devices should all be on dedicated circuits, such as "propane detector" & boiler protection.
I would guess that the circuit you had was a 20A fuse based on "slide-outs" being on this circuit.

My hat is off to you and your intelligent running of a new dedicated supply line to your fridge

Thanks for your post, it is folks like you that help everyone solve problems by educating others to safety concerns

[K7JV]

Great comments, "Fridge Defend". I was surprised to see what all was on that fuse, too. In the rats nest (and I mean rats nest beyond your wildest imagination), the conductor from the fuse module split into two circuits. I did not dig deeply enough to identify which loads were on which of the two branches that went out into the coach from that connection. Of the four loads, the refrigerator, the propane detector, the radio and the slide controls, only the refrigerator and the propane detector were reasonably accessible to test for continuity and/or voltage. The radio is buried in the bowels of the cockpit dash, and the slide control switches are in a module mounted in the wall of a cabinet above the entry door. I wasn't ready to go thru the gyrations to remove whatever would be necessary to be able to find those conductors and open the circuit to test for impedances or check for voltages. Instead, I chose the "easy" route and ran a new conductor pair. All is now good. (Actually, it wasn't really very easy, at all!!)

You are right about safety devices being best served by dedicated circuits. And the refrigerator should really be on it's own, as well. The radio and the slide controls could probably piggy back on most anything else. The slide control load on the circuit included only the switches and the small relay coils that they operate, so current requirements there were very low. The heavy current power sources to the contacts that then run the slide motors are on their own fuses.

The two amps load on the refrigerator was noted from a DC clamp-on ammeter, and the Norcold manual. Clamp-on ammeters really are not precision current measuring devices by any means, but it gave me a ballpark. I then used some vehicle turn signal bulbs to come up with a load that would result in about 2 amps from the 12 volt supply and used that to confirm the voltage was dipping at the refrigerator in about the amount that I was seeing with the refrigerator connected normally. My testing was far from laboratory-grade, but it gave useful enough numbers to identify the problem. An ohm-meter check from the wire connector at the refrigerator and the lug on the fuse panel confirmed the resistance value. It would be interesting to find out where the higher than expected resistance was in the circuit between the fuse and the refrigerator and/or the ground path from the refrigerator back to the coach ground. But whatever it is, it isn't nearly enough to be a problem for the remaining three loads.

Interesting that someone else is experiencing the same problem I was experiencing on a very similar coach. Leads me to think that Entegra had a bit of a design flaw in their power distribution design, even beyond the poor safety practice of combining the loads that they did.

Anyway, thank you for your comments. Again, all is good now, with our coach. Yay! Cheers and blessings to you!

PS: As a retired EE from the local power utility company who was responsible for the control and protection and auxiliary systems for 18 hydroelectric power plants, I especially appreciate your remarks.

[Fridge Defend]

Originally Posted by K7JV

Great comments, "Fridge Defend". I was surprised to see what all was on that fuse, too. In the rats nest (and I mean rats nest beyond your wildest imagination), the conductor from the fuse module split into two circuits. I did not dig deeply enough to identify which loads were on which of the two branches that went out into the coach from that connection. Of the four loads, the refrigerator, the propane detector, the radio and the slide controls, only the refrigerator and the propane detector were reasonably accessible to test for continuity and/or voltage. The radio is buried in the bowels of the cockpit dash, and the slide control switches are in a module mounted in the wall of a cabinet above the entry door. I wasn't ready to go thru the gyrations to remove whatever would be necessary to be able to find those conductors and open the circuit to test for impedances or check for voltages. Instead, I chose the "easy" route and ran a new conductor pair. All is now good. (Actually, it wasn't really very easy, at all!!)

You are right about safety devices being best served by dedicated circuits. And the refrigerator should really be on it's own, as well. The radio and the slide controls could probably piggy back on most anything else. The slide control load on the circuit included only the switches and the small relay coils that they operate, so current requirements there were very low. The heavy current power sources to the contacts that then run the slide motors are on their own fuses.

The two amps load on the refrigerator was noted from a DC clamp-on ammeter, and the Norcold manual. Clamp-on ammeters really are not precision current measuring devices by any means, but it gave me a ballpark. I then used some vehicle turn signal bulbs to come up with a load that would result in about 2 amps from the 12 volt supply and used that to confirm the voltage was dipping at the refrigerator in about the amount that I was seeing with the refrigerator connected normally. My testing was far from laboratory-grade, but it gave useful enough numbers to identify the problem. An ohm-meter check from the wire connector at the refrigerator and the lug on the fuse panel confirmed the resistance value. It would be interesting to find out where the higher than expected resistance was in the circuit between the fuse and the refrigerator and/or the ground path from the refrigerator back to the coach ground. But whatever it is, it isn't nearly enough to be a problem for the remaining three loads.

Interesting that someone else is experiencing the same problem I was experiencing on a very similar coach. Leads me to think that Entegra had a bit of a design flaw in their power distribution design, even beyond the poor safety practice of combining the loads that they did.

Anyway, thank you for your comments. Again, all is good now, with our coach. Yay! Cheers and blessings to you!

PS: As a retired EE from the local power utility company who was responsible for the control and protection and auxiliary systems for 18 hydroelectric power plants, I especially appreciate your remarks.

Thanks for your input

We need folks like you on iRV2. Dedicated to problem solving and nothing else.

One engineer to another, it is kind of comical that some have no clue when it comes to the right use of science combined with practical experience.

Our safety product, I recommend a 5A fuse on the front end of the controller. This protects everything down stream, namely the fridge.
Also, we have a voltage readout, this is because voltage drops are very common in RVs. This saves us and the end user a lot of time!

Please see some of our other posts, having the voice of science and reason kick in helps a lot

We are here to break some common misconceptions only