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B.C. · 01-15-2009, 08:54 AM

This is a note to the do-it-yourself people out there.

I had to replace the power board on my Norcold 1201 (SN-832171 and above). There are several wires attached to the board. Most can be identified like 12V+ and -, and those going to the gas valve. On the left side of the board (under the cover) there are 2 yellow and 2 black wires that disapear behind the cooling unit. At the least these wires should be labeled prior to removing them. I didn't. It appears that I crossed the two yellow wires because when reassembled (without the cover) as soon as the 12V+ wire was hooked up it popped the DC fuse. I had saved the 12V+ wire for last. After going over the wire connection points to make sure everyting was on the right posts I swapped the two yellow wires and everything is working fine on gas and electric. Norcold could have helped out by using different wire colors BUT.
Some of you are wondering why I changed the board. First, about six months ago the DC fuse blew for no apparent reason. We were operating on 50 amps with pretty constant voltage. The inside display was blank. I did the troubleshooting and tracked it down to the fuse. The next failure with the inside display blank I checked the fuse and it was good, and about every 15 or 20 seconds the board would click. I pulled the 12V+ wire and it stopped making noise. I left it off until we got home. Further diagnostics (and the Norcold service manual) indicated board replacement. One error I found in the troubleshooting charts was on page 9 in the lower right side of the page. There is a graphic indicating where to check the power to the display board. The instruction to unplug the display harness and check for voltage is wrong. The voltage comes from the power board.
As a side note the service manual does say to plug the yellow and black wires to the correct terminals but that is on page 40 where the troubleshooting is on page 9.
Hope this helps someone.

B.C. · 01-15-2009, 08:54 AM

This is a note to the do-it-yourself people out there.

I had to replace the power board on my Norcold 1201 (SN-832171 and above). There are several wires attached to the board. Most can be identified like 12V+ and -, and those going to the gas valve. On the left side of the board (under the cover) there are 2 yellow and 2 black wires that disapear behind the cooling unit. At the least these wires should be labeled prior to removing them. I didn't. It appears that I crossed the two yellow wires because when reassembled (without the cover) as soon as the 12V+ wire was hooked up it popped the DC fuse. I had saved the 12V+ wire for last. After going over the wire connection points to make sure everyting was on the right posts I swapped the two yellow wires and everything is working fine on gas and electric. Norcold could have helped out by using different wire colors BUT.
Some of you are wondering why I changed the board. First, about six months ago the DC fuse blew for no apparent reason. We were operating on 50 amps with pretty constant voltage. The inside display was blank. I did the troubleshooting and tracked it down to the fuse. The next failure with the inside display blank I checked the fuse and it was good, and about every 15 or 20 seconds the board would click. I pulled the 12V+ wire and it stopped making noise. I left it off until we got home. Further diagnostics (and the Norcold service manual) indicated board replacement. One error I found in the troubleshooting charts was on page 9 in the lower right side of the page. There is a graphic indicating where to check the power to the display board. The instruction to unplug the display harness and check for voltage is wrong. The voltage comes from the power board.
As a side note the service manual does say to plug the yellow and black wires to the correct terminals but that is on page 40 where the troubleshooting is on page 9.
Hope this helps someone.

"007" · 01-15-2009, 05:20 PM

Thanks for the info B.C. can always use from a DIY.

RV Wizard · 01-15-2009, 11:57 PM

The reason for the same color of wire (2 yellow and 2 black) is because there are two heating elements installed. Both are the same part # and are identical. If a lay person feels comfortable enough to troubleshoot or even repair problems this is great, especially in these economic times.
I warn those that there can be dangers, and problems can be created by not knowing all of the design and hidden integrations of systems present in todays coaches.
If you must replace wiring at least always mark and even take a picture of the connections if you have any doubts.