Norcold N621 Refrigerator blowing 3 amp fuse

[nvb572000]

We thought the problem was the heating element so we just replaced it. There is still a problem with the 3 amp fuse blowing each time we reconnect everything. Any suggestions? Thanks

[Jim_HiTek]

According to the schematic here: Norcold N62x, There can be 3 fuses. A 30 amp for the DC heater element if you have one of those instead of a 120 Vac heater, a 5 amp, and an 8 amp.

Nowhere can I find a 3 amp. Could be your problem is the fuse is underrated for the circuit.

[Old-Biscuit]

YEP^^^^^

The Norcold N6XX/N8XX Series uses a 5A Automotive Blade type DC fuse to protect circuit board
An 8A AGC (glass) fast acting fuse for the 120VAC circuit


**30A Auto Blade Type used for those 3 way models for the DC Heater Circuit


When you replace that 3A with the proper 5A and it BLOWS then you have an issue
IF that happens you need to troubleshoot if it is the circuit board or one of the DC components (gas valve, light, upper display,)
Unplug those leads from circuit board and try new fuse...
If it blows.circuit board is shorted
If not.plug each component leads in until fuse blows...that component is shorted
**If fuse blows it usually is due to short on the circuit board

[Fridge Defend]

Originally Posted by nvb572000

We thought the problem was the heating element so we just replaced it. There is still a problem with the 3 amp fuse blowing each time we reconnect everything. Any suggestions? Thanks

Let us know if your problem is fixed or not, we have extensive experience with this fridge.

Fuses do just get old, and as mentioned above, one needs to replace with the proper fuse.

Hope this helps

[Jim_HiTek]

Going to assume OP's eyes may be a bit like mine where I can't always see straight and a 5 can easily look like a 3 to me so that may be what went bad, but I'd like to offer some fuse knowledge.

With a magnifier,

1) if the fuse element seems to have a wobble in it instead of it being straight and mostly level? That may be one of very few factory defective fuses. Not quite connected on one end, works for a while, and a poor connection eventually causes it to break loose from the end cap. With an ohmmeter it measures infinity.

2) Second thing to look for if it's not 1), is an open in the fuse element you can see. The two ends curled up a bit somewhere in the fuse element. Maybe a bit of white fogginess of the glass under that open. Or the element has a wow in it so it's sort of drooping where the break in the element is. That's a current overload, and often is caused by say a 3 amp fuse used in a circuit designed for a 5 amp fuse. If it's actually a 5 amp fuse, then it could have been caused but something benign that won't happen again, and a new 5 amp is called for.

3) A short somewhere in the circuitry past the fuse will cause a break like 2), but in this case, there will be carbon black on the glass. The ends of the fuse element where the bread is will be mostly black too. It will for all the world look like there was a tiny fire inside the fuse. And there was. This type failure needs a bit more work than 2) because you want to find what caused the short before blowing a bunch more fuses while testing. (There are tools to avoid this though).

So with the old fuse in hand, OP should verify what it amps rating is, and try to discern how it blew, before replacing it too quickly. And never put a bigger fuse in place of what the circuit was designed for.

Yeah, I know, too much time on my hands. Sorry.

[Old-Biscuit]

Fridge 5A DC fuse is TAN and is a blade type





3A DC Blade Fuse is VIOLET

[Fridge Defend]

My 2 cents:

The easiest test for a fuse is to measure voltage, is there voltage on one side and not the other?

The second easiest is to just use an Ohm meter, of blown the fuse will read open (OL on most meters) between the blades.

The next easiest thing to do is to use your Ohm meter to read the side of the fuse with the load on it. Measure the Ohms on the output, use V=I*R, or I=12/R where R is the measured resistance in Ohms, this will tell you the amperage fuse needed, which is the I in amps that the circuit draws.

NOTE: When a circuit powers up, often the amperage goes up due to loads being switched on, this is where an amp meter is needed.

[nvb572000]

Our manual has it as 3 amp. We have unplugged items and when we plug in the green wire, one of the 12 VDC connections, it does not blow but if we plug in the purple, also a 12 VDC connection, with or without the green it blows the fuse. Any thoughts?

[Old-Biscuit]

What Year is your Winnebago/N621??

Your N621 does NOT have Items 16, 17, 18, 19 (N640/N840/N841 models)

Item 11 is the 12VDC+ and 12VDC- connections (from Battery/Fuse Dist Panel)...to supply DC to circuit board

That 'manual' does indicate the DC Fuse is a 3A (#9), a 5A AC Fuse (#8) and a 30A DC Fuse (#14) for 3-way Models N6/N8XX.3

Purple is the 12VDC+ wire
Plugging it onto the circuit board and 3A fuse BLOWS....SHORT on circuit Board
New circuit board required.


Why that manual indicates 3A/5A when ALL wiring diagrams show 5A DC & 5A AC?
Must be a change in production.......Older production models can get upgraded (higher fuse ratings) over the production years
Not downgrades (lower fuse ratings)
On EDIT:
Found 2 different Service Manual
1998 Printing indicates 3A DC/5A AC Fuses

2004 Printing indicates 5A DC/5A AC Fuses




So what year is your RV??????


2 different boards used based on serial number
#63218001
Fits all N62/82X models with a serial number below 8970880.

If your serial number is above 8970880, you need: 628661

**Both boards use 5A DC & 5A AC Fuses

[nvb572000]

It is a 1999 Brave. The serial number is 0980966.

[nvb572000]

Is this the board I should get 63218001 ?