Adding thermostat control to the refrig during DC operation

[Bill]

Many TM owners don't realize that when the refrigerator is switched to battery (12 VDC) operation, there is no thermostatic control. The refrig operates at max cooling all the time. Among other annoyances, this will freeze the food in the refrig. On another RV Owners web site, I recently ran across an article showing how a reasonably simple mod to the refrig will add thermostat control during DC operation. With the permission of that web site's owner, I copied relevant parts of the article. It is attached.

Bill

[Bill]

The author of the DC Thermostat Control document has expanded the idea to make a small improvement.

As noted in the above document, the original circuit draws a small amount of DC power even when the refrigerator is being run on gas. This is not a big deal unless you are boondocking for a long period. The updated approach requires one more relay, but eliminates that small DC power drain.

Bill

[Bill]

I have been reminded that several years ago, one of our members, Rickst29, developed a new and excellent approach to controlling the refrig temperature in both AC and DC operation. His approach provides a degree of control that is much better than the basic thermostat in the N300 refrigerator can provide. He outlined it in a number of very detailed posts here on the TMO Forum, including some in this thread.

www.trailmanorowners.com/forum/showthread.php?t=13490

I encourage anyone who is thinking of making a change to check out his writeups.

Bill