Norcold Control Box Wiring

Your Norcold fridge does not come from the factory with adequate boiler temperature protection. This page shows the different Norcold wiring schemes along with the recalls enabling one to determine how to wire the Fridge Defend by ARP Control.

Around the year 2000 Norcold refrigerators started developing problems that resulted in fridge failure. The majority of these failures were located in the cooling unit boiler area. As as a result, recalls of the refrigerators were mandated. One fact is evident, the recalls were not totally effective because the failures continued. The Fridge Defend addresses one of the root causes of RV fridge failure which can result in a fire. The Fridge Defend limits the cooling unit boiler temperature when installed, maintained, and operated correctly.

The following Norcold wiring schemes are provided so that the installer can easily identify the factory wiring scheme. Each wiring scheme is numbered for ease of communication if telephone or e-mail installation assistance is needed.


Table of Contents

REQUIRED TO DOWNLOAD INSTALLATION INSTRUCTIONS - WEB PAGES ARE SUPPLEMENTAL - EACH VERSION OF CONTROL HAS INTRICACIES REQUIRING THE WRITTEN INSTRUCTIONS.

Instructions: Some of the models of Norcold fridge are listed on the left, not all. Please scan the wiring schemes, if your fridge is not listed please use the Contact Us form. Click the link to the right to go directly to the wiring drawing for your fridge model.


Recall Wiring Example 1

Wiring Instructions and Symbols

This symbol indicates a dashed wire and a circle with cross-out.

  The dashed line/wire is how the fridge was originally wired.
  The circle with cross-out indicates to remove the wire and replace with the shown Fridge Defend wiring.


Recall Wiring Example 1

Wiring Scheme Number 1

(1) Starting at the RV, the RV delivers power to run the fridge and its controls. Please note that two wires will enter the cooling unit compartment, one power and the other ground. Because the color of the power wires vary by RV manufacture it is up to the installer to determine the correct wire color for the power and ground.

(2) The ARP will interrupt the power to the RV fridge in order to turn on and off the cooling unit heat source. The ARP can be wired anywhere along the +12VDC power wire. Click for Further Reading on ARP Function

(3) The Norcold recall is shown with only the +12VDC wires. The +12VDC wires are the only wires that the ARP Control will connect with on the Norcold recall box. Thus, the power supply, the Norcold recall box, and the ARP are wired in series with the power supply to the Norcold fridge controller (4).

(4) The Norcold fridge controller receives the +12VDC power from the RV power supply (1) via the ARP yellow wire. We show the Norcold fridge controller ground wire because this is a good place to ground the ARP control. We do not recommend grounding the ARP control at the same location as the Norcold recall (3).

(5) In order to make the wiring complete we show the cooling unit boiler assembly. Please note that the insulation around the boiler assembly is not shown. The ARP temperature sensor is clipped onto the boiler tube. The boiler tube is easy to identify because the boiler tube has the electric heater holders welded directly to it. The flue tube is usually behind the boiler tube on all Norcold fridges. One exception is the Norcold N3104 and N3150 series of fridges.


Recall Wiring Example 2

Wiring Scheme Number 2

(1) Starting at the RV, the RV delivers power to run the fridge and its controls. Please See Note in Scheme 1, Item (1)

(2) As opposed to drawing #1, the Norcold recall box can be wired directly to the Norcold control board (4) on the Norcold 1210 and other 1200 series fridges. For this wiring scheme the Norcold recall remains wired exactly as it was by the Norcold technician that installed the recall. Restated, the Norcold recall (2) terminals +12V IN and +12 OUT are wired directly to Norcold control board terminals LIMIT_IN and LIMIT_OUT. Where LIMIT_IN and LIMIT_OUT terminals are under the Norcold control board (4) cover.

(3) When the Norcold recall is wired directly to the Norcold control board (4), the ARP shall be wired inline with the Norcold control board power supply from the RV (1). Remove the +12VDC power wire from the Norcold control board and connect it to the ARP red wire. Now connect the ARP yellow wire where you disconnected the +12VDC power wire from the board in the last step. Click for ARP Wiring Basics

(4) Please note that for the Norcold control, the +12VDC power is delivered via the ARP. Also note that the ground for both the ARP and the Norcold control are on the same wire coming from the RV power supply (1).

(5) In order to make the wiring complete we show the cooling unit boiler assembly. Please see notes in Wiring Scheme Number 1 for further details.


Recall Wiring Example 3

Wiring Scheme Number 3

(1) Starting at the RV, the RV delivers power to run the fridge and its controls. Two wires will enter the cooling unit compartment, one power and the other ground. Because the color of the power wires vary by RV manufacture it is up to the installer to determine the correct wire color for the power and ground.

(2) As opposed to drawings #1 and #2, the Norcold recall for this wiring scheme is called a boiler housing thermal switch. The thermal switch is mounted on the boiler housing and will turn off power to the Norcold control (4) if the cooling unit compartment sees excessive temperatures due to an event like a fire.

(3) Because the thermal switch (2) is wired between the RV power source (1) and the Norcold control (4), the ARP is wired inline with the +12VDC power supply to the Norcold control. In this drawing the ARP is wired inline with the +12VDC power supplied to the thermal switch.  If it is easier, the ARP can be wired inline with the +12VDC from the thermal switch to the Norcold control. Click for ARP Wiring Basics

(4) Please note that for the Norcold control, the +12VDC power is delivered via the ARP. Also note that the ground for both the ARP and the Norcold control are on the same wire coming from the RV power supply (1).

(5) In order to make the wiring complete we show the cooling unit boiler assembly with the thermal switch. Please see note in Scheme 1, Item (5) for further details. Note that the ARP temperature sensor wiring is omitted in this drawing for clarity.


Recall Wiring Example 4

Wiring Scheme Number 4

(1) Starting at the RV, the RV delivers power to run the fridge and its controls. Please See Note in Scheme 1, Item (1)

(2) As opposed to drawing #3, the Norcold boiler housing thermo switch can be wired directly to the Norcold control board (4). For this wiring scheme the Norcold recall remains wired exactly as it was by the Norcold technician that installed the recall.

(3) The ARP control is wired inline with the +12VDC power supply. The ARP red wire will be connected to the wire coming from the RV +12VDC power supply and the ARP yellow wire will be connected to the Norcold control (4) where the RV +12VDC power was removed from the Norcold control. Click for ARP Wiring Basics

(4) Please note that for the Norcold control, the +12VDC power is delivered via the ARP. Also note that the ground for both the ARP and the Norcold control are on the same wire coming from the RV power supply (1).

(5) In order to make the wiring complete we show the cooling unit boiler assembly. Please see note in Scheme 1, Item (5) for further details.


Recall Wiring Example 5

Wiring Scheme Number 5

(1) Starting at the RV, the RV delivers power to run the fridge and its controls. Two wires will enter the cooling unit compartment, one power and the other ground. The ground wire (-12VDC) goes to the J3 terminal of the control box (2). The positive wire (+12VDC) goes to the J4 terminal of the control box. Please note that the power wires coming from the RV power supply may be any color depending on the manufacture of your RV, it is up to the installer to determine which wire is which.

(2) The Norcold control terminals are identified from top to bottom J1 through J9.

(3) The ARP control is wired inline with the +12VDC power supply. Ground the ARP green wire to terminal J3 of the Norcold control (2). Remove the power wire from terminal J4 and connect it to the ARP red wire. Connect ARP yellow wire to terminal J4 to complete the circuit. Please note, if you have a 3-way fridge that has a 12 Volt heater, a relay will be needed to control the 12V heater. We do not recommend using 12V heaters, please contact us if you have any questions.

(4) In order to make the wiring complete we show the cooling unit boiler assembly. Please see note in Scheme 1, Item (5) for further details.

If you have a 3-way fridge, please click on this link to see how to use a relay to power the 12VDC electric heater: 3-Way Fridge Relay


Recall Wiring Example 6

Wiring Scheme Number 6

(1) Starting at the RV, the RV delivers power to run the fridge and its controls. Please See Note in Scheme 1, Item (1)

(2) This is the Norcold refrigerator control box, for the late model 3-way fridge, remove the wire that goes between terminals 2 and 6.

(3) The ARP Control yellow wire will be connected to control box (2) terminal 2. The red wire will be connected to terminal 6. Click here for another example of wiring a Norcold 3-way.

(4) Click here for the boiler sensor install photos.

Click for ARP Wiring Basics


Wiring Scheme Number 7 | Polar 2-Way

Norcold Polar N7 N8 N10 Wiring

(1) Starting at the RV, the RV delivers power to run the fridge and its controls. Please See Note in Scheme 1, Item (1)

(2) This is the Norcold refrigerator control box.

(3) The ARP Control yellow wire will be connected to control box (2) terminal 2. The red wire will be connected to the wire that was removed from control box that supplied power to the control box.

(4) Click here for the boiler sensor install photos.

Click for ARP Wiring Basics


Norcold Polar 7LX 8LX Wiring

Wiring Scheme Number 8 | Polar 3-Way

(1) Starting at the RV, the RV delivers power to run the fridge and its controls. Please See Note in Scheme 1, Item (1)

(2) This is the Norcold refrigerator control box.

(3) The ARP Control yellow wire will be connected to control box (2) terminal 4. The red wire will be connected to the wire that was removed from the 3-Way Heater Board (4) terminal 4.

(4) 3-Way Heater Board (4) terminals 1 and 2 are both ground wires. Terminals 3 and 4 are both 12VDC power wires. Note that the wire that ran from the Fridge Control Board (2) terminal 4 to the 3-Way Heater Board (4) terminals 4 is completely removed and replaced by the Fridge Defend controller.

(5) Click here for the boiler sensor install photos.

Click for ARP Wiring Basics


Please use the Contact Us form found in the menu if you have any questions.