ARB 47l Fridge Repair (Thermostat)

[Bugjuic]

Background:

So I bought a 47l ARB fridge second-hand from someone about 2–3 years ago.

Last day of 2024 when heading out for a new year's party, I saw my fridge registering 60 Degrees Celsius, and was trying to bring it down to its set temperature (0 Degrees). Long story short, everything froze up.

Upon some research I found that before 2009 ARB made NON-serviceable thermostats (rather Thermistors technically). Also found many other manufacturers go this route where when they insulate the housing of the fridge, never designed it for the thermostat to be replaced.

Now the correct route (according to the inernet) is to order a new thermostat from ARB which they mostly ship to you at a reasonable cost.

With all this info in hand, I went to do some research and found that most fridges/icemakers etc make use not of thermostats, but rather thermistors which are a semiconductor type of resistor whose resistance is strongly dependent on temperature. You typically get NTC and PTC. NTC (negative temperature coefficient) and PTC (positive temperature coefficient), thus with a NTC your resistance decreases as they become warmer.

I found that household items such as fridges made use of a 10K NTC Thermistor which can be locally found at most electronic shops(communica etc.).

I had to pay a full amount of R15.00 for this item!

Anyway to get to this enclosed unit, you use a template from ARB:

thermistor fix template.pdf

(62.47 KiB) Downloaded 51 times

Other fridges may vary...

I opted for a dremel instead of a hole-saw.

And slowly "chiselled" out until I found the Thermistor:

Here I found they used a piece of Foil to reflect some of the heat, very clever:

Finally found the Thermistor:

Measured to make sure it was indeed broken, cut the wires (they do not have polarity), used heatshrink, and soldered the purchased one in its place:

Superglued the holder back in:

Tucked everything away:

Bought some adhesive foam and covered the hole with the piece I cut out:

Finally made everything neat:

And there we go, all working perfectly again. All for R15.00 fix...

Maybe this can help someone with a similar problem

[Paul#25]

Thanks for a very useful post.

[Mad Manny]

Thanks. I see in one Pic that you hit it with a hammer...

[BushWacker]

Impressive surgery Bugjuic !

Interestingly i had a similar problem earlier this year with my Snowmaster 35L whereby digital temp reading was variously erratic or steadily reflected a temp of abou 23 C .. I would then generally find fridge was closer to freezing Temp.
I did however have the fridge positioned on my Transmission Tunnel which can be fairly hot at times ...
however running the fridge indoors over Xmas everything was quite normal and cold Beers was order of day.

Will look at deploying an effective layer of insulation
when next using the fridge in the vehicle.

[Mad Manny]

Buy something that doesn't overheat the trannys tunnel Chas....