At 22 years old it's probably got so much dust inside, there is a blanket covering everything. Also the fan has probably died, they only last so long & it will have a blanket of dust on the back of the blades.
Replacing fan in 32L Engel fridge (it has a 24v fan):
I upgraded the fan in my 28L Waeco fridge with a larger 120mm Noctua industrial fan. More power efficient than the original & pushes more air & at higher pressure.
The standard Noctua fans are so efficient you may as well leave it running continuously. Running the fridge as a -18°C freezer the compressor will probably be running about 40 minutes every hour.
__________________
Procrastination, mankind's greatest labour saving device!
50L custom fuel rack 6x20W 100/20mppt 4x26Ah gel 28L super insulated fridge TPMS 3 ARB compressors heatsink fan cooled 4L tank aftercooler Air/water OCD cleaning 4 stage car acoustic insulation.
Hi, My 40 litre Engel is well over 20yrs old and is used at times as a freezer, the temp gets down to around minus 18c and does not miss a beat and the motor cuts in and out as it should to maintain that temp, mind you it does mainly just keep going.
I am right now using it as a freezer using 240v in the garage and when in the back of the Pajero it runs on the 12v rear socket and runs and freezes with no problem when travelling.
If we park up for a few days I use a 12v outlet from the caravan and the solar takes care of the house batteries and I will also turn it off overnight.
So I am not understanding why you are talking about using fans, can you explain a bit more re your query.
My 32Ltr is also 20 years old, and I agree totally with Rod Mac. Doesn't miss a beat. When I'm home in give it a blow out with compressed air; but that's it.
Best beer fridge I have ever had.
Have used it as a freezer on many occasions and works a treat.
When I was doing my research on fridges 20 years ago, a mate got a bit tired of me taking about fridges and which one to purchase; his comment at the time was "Hetho just go and buy a >>>>>>>ing Engel". It was good advise.