I Have an Older AC/DC Fridge That Is Misbehaving. Any Ideas?


Hi Jeff, I have a bit of a technical question I’m hoping you can assist with.  I have a Novakool ac/dc fridge circa 1988.  It works fine on shore power.  On 12 volt power it works intermittently, and is usually shut right down if I leave it for a day.  The voltage at the back of the fridge is good when it it running on 12V, but drops below 6V when fridge compressor turns off,  and will sometimes restart itself, but gets warm over long periods.  The voltage on the batteries is good (12v or higher) when it does this.  I can restart it by flicking the circuit breaker.  I was hoping the issue would be resolved with the new batteries but doesn’t seem to be the case.  I’m looking for some guidance on whether you think this is a 1) normal (do nothing), 2) a wiring issue you can assist with, 3) a fridge issue for repair or 4) I should just buy a new fridge. - Ben


Good detective work.  What you are seeing is NOT normal and is most likely caused by a bad wire or bad connection. To confirm this, you want to measure voltage at the fridge and at the battery when fridge is running. If the battery voltage stays above 12 volts and the fridge voltage drops to 6 volts, the problem is in between the battery and the fridge. It’s also possible, but very unlikely the compressor is drawing way too much power because of an internal failure. I suggest to run a temporary wire between fridge and battery to isolate the problem. - Jeff