I own a 19T 2000 Hi-Lo Tow Lite and have a few questions about the fridge.

#1. What position does the master switch need to be in when I am plugged into 120V shore power for the fridge to work on AC? (fridge nob is turned to AC)

#2. What position does the master switch need to be on when I am driving down the highway for the fridge to work (fridge nob is turned to AC).

#3. Is there any way to know if the fridge is working on 120V OR when running off truck down the highway, other than to see if the fridge is cold?

I may be wrong, but I think the Master Switch can be in any position if you are plugged into shore power and running the fridge on AC power. I'm about 100% sure the Master Switch only controls 12V DC power.

Now, if you're driving down the highway, you are not plugged into Shore Power, so the fridge knob must be turned to DC for it to work on electrical power. Again, though, the Master Switch can be in any position, because the fridge circuit is not routed through it.

You could also be running the fridge on propane if you are not plugged into Shore Power. Again, I think the Master Switch is not a factor if you are using propane. It's not a good idea to runt the fridge on propane though while towing because the open flame is a hazard when you stop for gas at a filling station.

If you listen at the outside vent, you should hear the exterior fan running if the evaporator at the rear of the fridge is hot enough. That's one way to tell it's running. Mine has a light on the panel that lights up if it is not working properly. I also have a wireless thermometer transmitter inside that tells me if the fridge is working properly.

- Jack

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Hi-Lo 1707T - Tire Minder TPMS on Tow Vehicle and Trailer, 300W Solar Battery Charger, Equal-i-zer WDH, Progressive Dynamics Converter, Fan-Tastic Fan, LiFePO4 battery 12V DC Electrical System, SoftStartRV mounted on A/C
2024 F150 Platinum FX4 3.5L PowerBoost SCrew

Thanks for the response. I don't think my fridge has a DC setting. I turned it but it didn't seem to.

If your fridge is the original one that was installed in HiLos, it should be able to run off three different power sources - AC (shore power), DC (HiLo battery or tow vehicle battery) and Propane.

I don't understand your phrase: "...I turned it but it didn't seem to.". Turned what? To where? Didn't seem to what?

There IS a 30 Amp inline fuse in the DC 12V line that runs directly from the battery to the fridge. Is that fuse OK? You likely find that fuse behind the fridge after you take the ventilation intake panel off.

- Jack

Thanks Jack. I found the DC option for my fridge as I moved the dial further around. I was surprised it was so far separated from AC, OFF, GAS as I had to turn the dial considerably farther around before it indicates the DC setting.

I'm pretty sure I have everything working now. These fridges are really amazing in that they can work so many different ways. This is my first RV so a bit of a learning process.

You are most welcome! I'm glad you figured out how your fridge works. I agree, they are pretty amazing!

Just a wee warning - the fridge pulls a fairly high Amp load running on DC. Use propane or AC when camped, save the DC for the road. And, I ALWAYS disconnect my Tow Vehicle power cord before I try to raise the top of the trailer or use the front jack to level the trailer. It is VERY easy to blow the Tow Vehicle's 30 Amp fuse in the trailer battery charging circuit if you try to put a combined fridge, lift motor, or front jack draw on it.

- Jack

It’s suggested to run the fridge on A/C for 24 hours (overnight?) to cool before traveling…depending on the length of drive we would reduced the level of cooling while traveling. Fridge stays cold during traveling with door closed and we never had an issue with the freezer or fridge. We also used a small battery operated fan to help move cold air.

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Elaine and Bill Stevenson
Former HiLo-Classic 310S
2011 Toyota Sequoia