Norcold reefer

[flyfisher-SMB]

On a recent trip, I noticed my Norcold reefer (model DC 0051) was running continuously. It was keeping stuff cold, but wouldn't cycle off. It was set at "3" on the dial, if I turned it down to about "2 1/2" it would stop, and then cycle on after about 15 minutes, and then wouldn't cycle off again until I fiddled with the thermostat.

This is the first problem I've had with the reefer since I bought The Van new in 2005. Any thoughts before I start messing with it? Of course I don't know what I would be messing WITH, so all ideas are appreciated.

thanks

Tom

 

[photographix]

It might be as simple as dust in the adjustment knob, which would cause intermittent contact, or odd behavior. When this happens on a radio with a rheostat volume control, the volume will be wildly nonlinear.

Try turning the adjustment knob back and forth rapidly through its full range many times. This might be enough to knock the dust out.

 

[1der]

Check the coils for dust that may have accumulated which decrease efficiency and cause it to run more often? Also, check to make sure the air passages / vents are clear to the condenser area. Just a couple of ideas.

 

[DougGuy]

Might be a few months late with this but I just joined here. We have a DV441 in a 2001 SMB that runs and doesn't want to cycle until it's turned all the way down on 1 or 2, and it keeps the box 30° inside, and down to 25° at night when the ambient temps drop.

I found a troubleshooting guide that listed the specs for the thermistor in 10° ranges of temperatures, and using that I figured out that the thermistor on ours is pretty much not within those acceptable ranges. There is a connector you can disconnect and with a multimeter you can read the DC resistance of the thermistor when the box is cold, I bet you will find your thermistor is outside the acceptable range.

While looking for parts to see if the thermistor could be replaced, I came across this Articca adjustable thermistor and ordered one since it sounds from the description like it will let you control the temps of the box from the adjustment. All I can do it try it, since ours is not working right, and it seems like the only problem with it is that the resistance of the factory thermistor is off.

http://www.snip-the-tip.com/NorcoldThermistor.htm

I have had our fridge sitting in my workshop on a table running for a few days, other than it keeping the box too cold for anything not to freeze, it is cycling and working perfectly.

Since the adjustable unit was just ordered this morning, I should know in a week or two if it is fixed. $26 beats the crap out of $700 for a new fridge!