2019 Thor 29m refrigerator main control board

Machinetools1 · 09-26-2019, 02:58 AM

I was getting the motorhome ready for a week long camping trip. We are going to be boondocking more than at hookups. I ran the refrigerator on propane to make sure she was working. I transferred back to electricity and it would not transfer back. It was only going back to propane. I checked to make sure I was getting 110 volts to the plug in for the refrigerator and I was. That's when I found this. The mother board was burned up. Anyone had this problem.

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javelin · 09-27-2019, 04:23 PM

I see no comments on your post so far. Hopefully you are still under warranty and can get a replacement board quickly. I am actually having problems even finding your Norcold power board part number (from your picture) on line (maybe too new or I gave up too soon?). I am curious what F3 actually powers on that board. Most of the Norcold schematics that I see on line are the 2 way (propane and 120vac - 2 fuses and no F3). I wonder why this board looks like it overheated the resistor beside fuse F3? I have read where Norcold says not to overtighten the power board cover screws......so maybe someone did that and hairline cracked the board causing some overheating high resistance connections. I guess when you replace the board you might be able to determine obvious board issues.

Machinetools1 · 09-27-2019, 08:32 PM

Thanks for the reply. I did call Thor and it is under warranty. They advised me to take in in the shop for the repairs needed. I did not feel like having the motor home sit at the shop for 2 weeks waiting for repairs. I am going on vacation for a week and wanted it fixed and taking it to the repair shop would have voided my vacation. I contacted The Nor cold guy and purchased a board for $150.00. This part should be here on Saturday or Monday. I will go ahead and put it in myself. If the problem persists I will go ahead and take the motor home in for warranty service on the refrigerator after my vacation. I saw the mounting bolt was loose when I was inspecting the circuit board. When I replaced the new board I was going to make sure I tightened the bolts down. Thanks for giving me that tip of information about running those screws loose.
I am not sure what the third fuse is used for. This refrigerator only runs on electricity and propane.

javelin · 09-27-2019, 08:56 PM

Hi, well I don't want to wreck your vacation, but be careful on doing your own repairs on the OEM board (currently under warranty) without getting Thor's OK first as they may not honor the warranty if they see the original board has been "played with" or already changed out. I have not had much dealings with Thor on warranty issues since my coach has amazingly been pretty reliable other than a few items the Dealer fixed under warranty when I bought it new. For example they may agree to refunding the cost of an alternate power board to expedite your vacation plans if you ask.....but if you proceed without Thor consultation they may cur you lose on this one.....they don't know if you "may" have caused the failure in other words. Just saying it might be wise to ask first and then you are still covered or at least compensated for the new board you are buying. Other folks may have better suggestions based on their dealings with Thor and maybe they will chime in with suggestions.

**16ACE27** · 09-27-2019, 09:02 PM

Quote:

Originally Posted by javelin

Hi, well I don't want to wreck your vacation, but be careful on doing your own repairs on the OEM board (currently under warranty) without getting Thor's OK first as they may not honor the warranty if they see the original board has been "played with" or already changed out. I have not had much dealings with Thor on warranty issues since my coach has amazingly been pretty reliable other than a few items the Dealer fixed under warranty when I bought it new. For example they may agree to refunding the cost of an alternate power board to expedite your vacation plans if you ask.....but if you proceed without Thor consultation they may cur you lose on this one.....they don't know if you "may" have caused the failure in other words. Just saying it might be wise to ask first and then you are still covered or at least compensated for the new board you are buying. Other folks may have better suggestions based on their dealings with Thor and maybe they will chime in with suggestions.

Well since the refrigerator is not under "Thor's" warranty, but Norcold's (or whoever the fridge manufacturer is) he doesn't really need to deal with CW or Thor. He can get it repaired at any RV shop (including mobile techs) that are authorized warranty providers for that brand of fridge.

OldWEB · 09-27-2019, 09:29 PM

If it is, then F3 is suppose to be the fuse for the ac heater energized through relay K1.

Stay cool

Machinetools1 · 09-28-2019, 02:32 AM

Old web

Can you explain to me what is an ac heater and how it works. Also what fuse 3 does.
Thank you.

**16ACE27** · 09-28-2019, 02:43 AM

Quote:

Originally Posted by Machinetools1

Old web

Can you explain to me what is an ac heater and how it works. Also what fuse 3 does.
Thank you.

An "AC heater" is the heating element in your fridge that is powered by 120 Volts AC when plugged in to create the heat the propane does when the fridhe runs on propane. This heat is what causes the fridge to cool in this type of absorption refrigeration cycle.

As I understand it, fuse F3 is for the DC control power that latches the relay to supply the 120 VAC to the heating element.

Machinetools1 · 09-28-2019, 02:50 AM

Thank you very much for your reply. I was hoping the circuit board had some type of short in it. This was not caused by something else in the system causing the circuit board to melt.

OldWEB · 09-28-2019, 05:28 AM

I was unsure on how to upload an image, but was hoping you had the reefer manual, that shows the wiring diagram for the control board.
But the AC comes into the control, goes through the 8 amp F3 fuse, then though the K1 realay contact and then out of the control board to the heater.
Your picture does show a resistor also appearing burnt... are the two related? That is the question.

Machinetools1 · 09-28-2019, 06:11 AM

Thanks for your input. I do have the wiring info on the fridge. That burned relay must have something too do with the transfer from electric to gas. The propane is working now so I am gonna run it for now. When I get back from my vacation I will check into getting it fixed. Thanks again for everyone's input.

BASSMAN · 10-10-2019, 12:03 AM

there are several Youtube Videos on RV refrigerators, I learned something on testing the heating unit, they by pass the control board completely and plug the 120 volt AC heating element into a extension cord and leave it over night, put a dish of water in the fridge before you start and the next moring the water should be frozen, if not you have a bad heating element, its a simple test, why the board fried is a up for debate

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