Winnebago View Norcold Problem - Why?

gohusaberg said:

Exactly. That's what I'm saying. I want it to do what it's designed to do. That's why we paid $120K for a brand new RV with bells and whistles. Amazingly, the darn thing is still working properly 90% of the time. I am finally getting around to ordering the new board now because I have had to replace a melted 20A fuse 3 times now which requires me to take the whole thing apart. I have been talking to the ARP guy, Paul. I will likely just spend the money and order the entire upgraded board and converter from them. It 100% fixes the problem. Thank you Winnebago and Norcold for selling me something that you knew had years of documented issues. (That's where the attitude part came from) LOL

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Paul modified my board by removing the fuse replacing it with an external 25 amp fuse and external hookup to the relay. Mine burned the 12v connectors where they plugged into the LP igniter. Fire hazard. Just went on a 300 mile trip all is well now.

That is the right way to do it! Caution to DIYers though - this trick will not work as well on the earlier version of the board because the board has a hall effect sensor to detect the heater current. It will throw an error if this sensor is not spoofed somehow. Easiest way is to run heavy wire under the sensor.

rollerbearing said:

That is the right way to do it! Caution to DIYers though - this trick will not work as well on the earlier version of the board because the board has a hall effect sensor to detect the heater current. It will throw an error if this sensor is not spoofed somehow. Easiest way is to run heavy wire under the sensor.

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Rollerbearing - I received this “correction” from Paul at ARP

The reason we wire the control the way we do is so that the current sensor is inline with the new relay.
All of the controls have current sensors, the only difference between the controls is the display and the way they made the igniter for the LP gas.

Please post this answer and a link to our home page: https://www.arprv.com/

Gotcha - I looked pretty hard at your board and couldn't see the hall sensor.

Also, I made an assumption that the external relay had the high current power going directly to it and that it was wired directly to the heater. Bad assumption - when I traced the wiring it was clear that the power goes to the board, then to the relay, back to the board and then to the heater connector.

So yes it would preserve the current path needed by the hall sensor (that is evidently still on the board).

rollerbearing said:

Gotcha - I looked pretty hard at your board and couldn't see the hall sensor.

Also, I made an assumption that the external relay had the high current power going directly to it and that it was wired directly to the heater. Bad assumption - when I traced the wiring it was clear that the power goes to the board, then to the relay, back to the board and then to the heater connector.

So yes it would preserve the current path needed by the hall sensor (that is evidently still on the board).

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Here is how the board is rewired

Relay the way it is wired now.

Black is the relay coil ground.
Red is the relay coil power.
The yellow heavy gauge wire without the fuse going to the relay goes to the 12VDC heater + on the circuit board.
The yellow heavy gauge wire with the fuse goes to the HC 12VDC connection on the circuit board, but within the circuit board there is an amp measuring circuit. If this amp measuring circuit is not inline with this wire, you get the error message. This is why the entire HC 12VDC wires cannot be off of the circuit board.

Hey everyone,
Though this thread has been dormant for a while, I found it to be very useful, so thanks all! I thought I'd add my personal findings here since there is some uniqueness. I own a 2014 Winnebago Via with 24k miles and I recently started experiencing problems with DC mode on my Norcold 3150. In my case, the front LCD display panel would start to blink after some run time in DC mode. The blink was in a "mostly-off" way, meaning the power appeared to cut out, and then in 1 to 3 seconds, it would very briefly come back on, and then go back off. This made it difficult to actually turn the unit off or change the mode away from DC via the front panel controls. You had to time the control inputs with the brief on-state.

What I have concluded is that (as Showkey mentioned earlier) the low quality spade connectors used for the 20A fuse (F1) were the root of my problems. But I'll take it a bit further to explain the display blinking. As shown my first photo (01), the 20A fuse (removed from it's female spade connectors and sitting on top of the black relay) is discolored from the heating. The fuse leads were getting hot enough to melt the plastic framework (not shown in pics) that surrounds the five male spade connectors that are directly below the fuse, but not hot enough to actually melt/blow the fuse. I'm going to guess that the plastic (PVC?) framework was reaching temperatures of more than 200C to melt as it did. What this means to me is that F2 (the square yellow 1.1A PTC resettable fuse that is directly below F1, and is in series with the low current logic supply voltage) was reaching EVEN HIGHER temperatures. So my theory is that the heating from F1 was raising the temperature of F2 sufficiently to lower it's trip threshold to something below the system's normal current draw in DC mode. The result is that the LCD front panel will go blank from power loss. This in turn cuts the black DC heater relay off and allows things to cool. Ultimately, this keeps the temperature of F2 at a reduced trip current threshold which leads to the cycling of the unit's power until it is manually turned off or changed to a different mode.

My solution: Since my Via already has a 20A fuse (in the RV's fuse box) that exclusively feeds the fridge's DC high-current circuit, I elected to ELIMINATE the on-board 20A fuse altogether, as the on-board fuse provides no real function IN THIS CASE. Again, this is because my RV already has a dedicated 20A fuse feeding this circuit. I bypassed the fuse as shown in the second and third (02 & 03) photos using 12AWG solid copper from Romex household wiring in order to minimize resistance in this path and also to provide some heat spreading, in case the PCB traces were marginally sized as discussed elsewhere in this thread.

Test results: I installed the board without the protective enclosure and operated the fridge in DC mode with its doors open (to keep the heater running) until temperatures settled. What I found was that the PCB area of F2 (the most burnt area of the PCB - marked with a yellow "B" in the third pic) now experienced only about 10F temperature rise (using an IR probe) above the neighboring (cool) areas - so this seems just fine. In fact, the area marked with a yellow "A" is now the hottest spot on the PCB in DC mode - it sees about 30F rise. Maybe this is due to the (black) relay's COIL power dissipation when energized (DC heater is on), since the temperature rise disappears in the LP/AC modes, and the DC heater traces do not appear to be routed up in that area. Either way, it's not a newly-hot area, and I don't see any thermal issues with this fix.

Hope this provides a little more insight to those interested - or at least to those that are dealing with this version of the power board. I know nothing about the newer version(s). Makes me think that simply finding better spade connectors would be an acceptable fix. The 20A fuse in my Via's fuse box (feeding this same circuit) does not get warm at all. In my case (having a dedicated 20A fuse in the coach), I think F1 only reduces the system's reliability.

Our 3150 (same generation) experiences the exact same symptoms and although we suspected the 20 due to other information we found all we need to do now is figure out how to remove the board to make the modification, and determine if our '14 View has an external 20.
Thanks for information and such a great write up!

Thanks, Winnie. Winnebago has the wiring diagrams on their website for free download, though they can be difficult to interpret. My fuse box is clearly marked for the 20A refrigerator fuse, as well as a 3A for the low-current circuit. I would add that if your View's fuse is greater than 20A, then there is some added risk to eliminating the PCB's fuse (and I'd think twice about doing it - especially if the larger fuse is feeding more than the fridge and cannot be downsized to 20A), as you are increasing the maximum current that the board could experience in a failure situation. Finally, once you think you have located the fuse, put your fridge in DC mode with the coach's 20A fuse pulled - you should get a flashing battery sign in the front panel, indicating that you have pulled the correct fuse.
Best of luck!

Via25Q said:

Thanks, Winnie. Winnebago has the wiring diagrams on their website for free download, though they can be difficult to interpret. My fuse box is clearly marked for the 20A refrigerator fuse, as well as a 3A for the low-current circuit. I would add that if your View's fuse is greater than 20A, then there is some added risk to eliminating the PCB's fuse (and I'd think twice about doing it - especially if the larger fuse is feeding more than the fridge and cannot be downsized to 20A), as you are increasing the maximum current that the board could experience in a failure situation. Finally, once you think you have located the fuse, put your fridge in DC mode with the coach's 20A fuse pulled - you should get a flashing battery sign in the front panel, indicating that you have pulled the correct fuse.
Best of luck!

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Thanks again, for the additional information. We will report back if we find the same solution works in our View.

Per Via25Q method, I just did the same thing. And, the fuse was black on one side and the board darkened, but the system still worked, but I am sure it was on it's last leg.

Seems to be working just fine, so far, as I tested it in it's various modes.

Thanks Via25Q.

OK, to clarify another mystery: After some lost sleep on why area "A" on the PCB was the hottest spot on the PCB (the black relay's coil power doesn't quite cut it), I recalled that the IR thermometer that I used (a mid-grade combo digital voltmeter/IR thermometer which I keep in my RV) does not accurately locate the measured temperature at close distances. A better quality meter confirmed that the actual hot spot is closer to the midpoint between points A and B in "03.jpg" above. This makes much more sense, as this location is literally surrounded by the high-current-carrying copper trace between F2 and one of the black relay's contacts.

This changes neither my earlier conclusions, nor my fix - I just wanted to correct the measurement error on my part...

I'd also like to reiterate that this mod/fix must NOT be performed if there isn't an external 20A fuse feeding this circuit! And don't buy those cheapo no-name fuses off eBay. I tried that once on a kit of 1A to 30A automotive fuses. Upon receiving them, I noticed that the fuse element within them all looked surprisingly similar in size. So I tested them and could not get ANY of them (even the 1A fuses) to blow with 30 amps continuous current!

Cheers!

Another work around would be to move the AC power to the Inverter. The AC is 4 amps and would work, I doubt the step inverter would cause an issue on my 15 G?
I had a fuse blow three years ago and replaced it. I also had a bad therm switch ( mounted on the right top of the heat fins. ) my cooling fan did not work, now works correctly. The heat could have caused an issue? A year later the AC fuse went out. I replaced it. I don't like the cover on the PCb. I wish it had a heat sink. I keep fuses with me and it's not to hard to replace a fuse. I guess WGO likes compressor fridge and Mercedes, no Riverpark Nav on the new Sprinter.

It is actually not necessary to remove the fuse. Doubling up all the +12 high current traces going in and out of the relay with 12 gauge wire will solve the issue. The heat generated between points A and B is due to the inadequacy of the single sided trace carrying +12V into the 12 volt relay. That is why it gets hot. It is also why the fuse gets "burned" on that side. Beefing up the traces keeps this heat from occuring and also allows the heat generated by the small voltage drop in the fuse to dissapate. The +12 trace leaving the relay is double sided and does not get as hot. For good insurance it is wise to go ahead and wire it with heavy copper wire and do the same to the heater ground trace.The current path that gets hot between points A and B must be followed closely with the wire in order to allow the on-board hall effect sensor to continue being able to detect the heater current. The hall sensor is the shiny dime sized square next to the 12 volt relay.

It is also perfectly acceptable to remove the fuse and bridge it as shown - so long as the fuse's protection is exactly duplicated elsewhere (ie the power panel or external fuse holder).

Wine Country said:

Another work around would be to move the AC power to the Inverter. The AC is 4 amps and would work, I doubt the step inverter would cause an issue on my 15 G?

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I like the idea of having an emergency option (maybe install a second receptacle in the fridge's bay) for using the inverter. Though it's likely to add another 20% to the battery load from going through the conversion, and thus make the alternator work harder when driving, it does provide a couple of advantages:

1) You can run the fridge for a short time (in a pinch) off the house batteries while parked without shore power or porpane.
2) You can run the fridge while driving if your DC mode has failed - and avoid propane on the drive. I've occasionally gotten a propane failed on my fridge while driving in very high wind, and I think it's simply due to the flame being blown out or failing to start due to turbulence up through those vent panels. So, even though the propane consumption by the fridge is very low, I dislike using it while driving.

I would still want to apply some sort of fix to the 12v mode or at least remove the fuse to eliminate the heating in case the fridge does try to run in that mode - otherwise the PCB could eventually destroy itself. I think it's a several hundred dollar board.

Wine Country said:

...I also had a bad therm switch ( mounted on the right top of the heat fins. ) my cooling fan did not work, now works correctly. The heat could have caused an issue?...

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The therm switch is designed to take that heat, but it's a pretty simple thing and they do fail.

Wine Country said:

...I don't like the cover on the PCb. I wish it had a heat sink...

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Unless you will never drive in bad weather, dusty/windy conditions or high humidity, I'd leave that cover in place. The actual heat generated by a properly working board is easily dissipated through that enclosure, and though the board is conformal coated to guard against the elements, it's never a good idea to unnecessarily expose sensitive electronics.

rollerbearing said:

It is actually not necessary to remove the fuse. Doubling up all the +12 high current traces going in and out of the relay with 12 gauge wire will solve the issue. The heat generated between points A and B is due to the inadequacy of the single sided trace carrying +12V into the 12 volt relay. That is why it gets hot. It is also why the fuse gets "burned" on that side. Beefing up the traces keeps this heat from occuring and also allows the heat generated by the small voltage drop in the fuse to dissapate.

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I agree and disagree. Per my original post, I believe that the problematic portion of the heat is caused by the poor spade connectors that were used to socket the fuse and the resistance of the connection that is made to the fuse by the spades. So the fuse can remain as long as the spades are replaced with a better quality item. Yes, all things equal, single-sided routing will cause more heating, but that SS trace is also a bit wider than the double sided traces. The 30F rise that I measured is in the CENTER of the U-shaped trace, not below it where the fuse is, and is in no way enough to cause discoloration of the PCB. My fuse was burned on both sides - yes the left side moreso, probably due to an additional 20F on that side. Given relatively heat-free fuse connections (or no fuse at all), I think the board will do fine as designed, though both you and I would have put more copper in that path had we designed the it.

It'll work either way. Just saying you don't need to remove the fuse.

rollerbearing said:

Supplemented all high current traces with 2 pieces of 14 gauge solid copper. No more hot spots on board. Tricky soldering all that heat conductor. Had to use a soldering iron in each hand applied simulataneously. Anyone doing this be sure and follow the current path under the previously mentioned hall sensor - don't take the straightest line shortcut.

Debated the external fuse connection. The thing is our power distribution panels use similar fuse connections and they seem to do fine - no scorching of the 20A dc fridge fuse in the main fuse/AC breaker panel. Decided to give the existing ones another go. The fuse connectors on the fridge board were full of conformal coating from when they sprayed/dipped the board. Ran a dummy fuse in and out a bunch of times to scrape this crud out. Pinched the holders tight again and jammed in a new fuse. Voltage drop across fuse is now 0.1V - a little more than the 0.06V I knew would be there, but a whole lot better than 0.2V! Buttoned it all back up and all is working fine now - we'll see how long she lasts.

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This is a two year (and 20,000 miles operating on 12v DC) follow up photo of the fuse I inserted in the above post.

And the mods on the back.

Either way works fine I am sure. I do like your way because it is sweet and simple and is a way around a burned beyond use fuse spade connector. It also makes a lot more sense to just bridge that there and put an external fuse holder in the 12v high current line versus soldering in a couple wires where the spades were and bringing these out to a fuse (the ARRP way if I recall correctly).

And this is the original fuse and its orientation as installed by Norcold showing again the one-sided burning.

Rollerbearing:
Nice! Like you say - six of one, a half dozen of the other...
And thanks for the post - I hadn't seen the PCB bottom pic on your mod.

Via25Q said:

-- I believe that the problematic portion of the heat is caused by the poor spade connectors that were used to socket the fuse and the resistance of the connection that is made to the fuse by the spades. So the fuse can remain as long as the spades are replaced with a better quality item.

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When I just accomplished your mod, I looked closely at the spade connectors, thinking if OK, would just replace the fuse. The spades themselves looked fine, and just the plastic part above was blacked out. The spades didn't look burned or heated, and had pretty deep scrapes caused by the female part of the connector. My feeling is the spade part is OK, BUT, I got scared and decided to do the jumper, because it isn't easy to get in there and get to or remove anything.

And, I do have the 20 amp fuse upstream, as you recommend.

Per the fuse tables the 20 amp fuse has an expected voltage drop of 0.06 volts at 20 amps. That is 1.2 watts. Not a huge amount of heat, but if the traces can't carry it away or if the traces themselves are getting hot (as they are) I can see it slowly cooking the fuse. IMO this doesn't necessarily have anything to do with the quality of the connection to the fuse - although it can certainly cause additional further problems if the connection is poor.