Cabin and cockpit fridge not operating at 12vdc

[Ryanengr]

Both refrigerators in my 2000 340da run great in 120v. But when switched to 12v, I get nothing. As I am new to large boats, figured I'd ask for help in looking at the simple/stupid/easy b4 I go ripping things apart.
Yes - 12v refrigerator breaker in cabin is "on" and no signs of being tripped.
Yes - same breaker down in the bilge shows no signs of being tripped.
Could one of the switches itself be bad? Someplace else I should look...?

Thanks!

 

[CliffA]

could be as simple as weak batteries.....you may want to have your house batteries load tested or just replace them if they have some age on them....

I believe there is a switch in the fridge that automatically switches to 12VDC power when 110VAC is not present....maybe that switch is defective....you could monitor the power coming into the compressor when you disconnect the 110VAC power supply....if you do not see any DC voltage coming into the compressor that may indicate the automatic switch is defective....hopefully others more experienced in electrical troubleshooting will chime in with suggestions......

but it would be strange to have this switch go bad on two fridges at the same time.....

cliff

 

[ClarkGriswold]

I am in the middle of changing our batteries on my 240 with a similar issue, albeit with just one fridge. Will let you know if the new juice helps


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[Boater420]

If both fridges are doing the same thing it's likely the batteries. I'd start there by fully charging the batteries, then load test them properly. Without strong batteries there's no way both refrigerators will run in DC for very long.

 

[Cincy Aquaholic]

I had this issue on my last 290 and have this issue on 1 fridge on my current 290. Either of these issues may be the same as yours so here's what I found out. On my old boat, the "switch" (its part of the fridge electrical supply) that keeps the fridge on when you change to DC 12 volt power went bad. I checked this by pulling the fridge and confirming power to the fridge and other appliances from that power source. So, it wasn't bad batteries or breakers. it was the fridge. I read on here that that is not uncommon. I never replaced it so I left it as is. While it would be odd for both to go out at the same time you don't say that. Just that they both don't work. So, don't rule that out. My new 290 apparently has an issue in the EIM under the helm. I checked voltage at the circuit breaker directly that supplies power to my cabin DC circuit for the fridge and TV and it only reads 3 volts. So, I need to sort that out. If you have EIM with these breakers, pull the breaker and check it directly. If there is correct power there then maybe a defective breaker.