Norcold 3-way fridge in 2007 T@B

Raybro

We have a 2007 T@B with a Norcold three way fridge. "Seems" to work fine on propane or 110v.
IF, the trailer is unplugged from a 110v source, and I have an  interior sconce light turned on, If I switch the fridge on to 12v, the interior light goes out, ( as in no 12v power ), if I now plug in the 110V with the fridge still on 12v, the convertor fan comes on, like the convertor is working very hard to keep up with the 12v draw.
If I am unplugged, when I turn the fridge on and the lights go out, if I turn the fridge off I get no lights until I plug in again.
It sounds to me like the fridge is drawing way, way, too much on 12v and the convertor shuts off the circuit for self preservation.

Has anyone run into this before? Is the fridge truly hooped?

Sharon_is_SAM

The 3 ways on 12v are notorious for their heavy draw.  I am not familiar with the differences in converters used in the 2007 vs current models.  I do know that it is recommended to turn off everything before connecting or disconnecting power to avoid surges and blown fuses.  The current manual recommends not turning on 12v until you have connected your 7 pin and your TV is running and to turn off your frig before turning off your TV to avoid battery drain.  So, the 12v is strictly used during transport and even then many Tabbers have reported problems with adequate cooling and/or battery drain.  

Raybro

Thank you for the reply Sam. I did notice that the battery voltage drop after just a few minutes was significant.
I strongly suspect that the fridge is drawing way more than it should. We'll work around it for now. Thanks again.

Sharon_is_SAM

@Raybro, part of the issue is that while on 12v, there is only 1 temperature set point (I understand no thermostat control).  The discussion linked may be helpful.  Also, search Norcold wiring.  

https://tab-rv.vanillacommunity.com/discussion/comment/71750#Comment_71750

Photomom

You might have your battery tested if you haven't done that.

Rokko16v

We experienced similar problems with our 2009 T@B. When you measure current, the fridge only draws about 1.5 amps on AC mode. However in 12V mode it draws nearly 15 amps! (According to the repair manual, I have not verified actual values). Of course it works the best on 120V or Lp. I guess the 12V mode is when you are towing?

Sharon_is_SAM

Yes, the 12v mode is used during towing.  Best to reduce your voltage loss from the alternator by using 8 - 10 gauge wire for your charge line and it is important to have an adequate alternator  - both of these go a long way to keeping your frig cold and your Tab battery charged.