Truck not delivering power to trailer

[Tardigrade]

When I move the trailer I have to switch the fridge to battery since the fire goes out. If I go a long distance when I get there my batteries are dead because of the drain from the fridge. I was under the impression the truck should be delivering power to the trailer but it's clear that's not happening. I'm looking for advice on troubleshooting this.

Some details. It's a 2014 Tundra and a 2021 Escape NE. I'm looking at the battery monitor and I can see the fridge drawing about 18 amps, truck running or not.

Thanks in advance for any suggestions.

[brroberts]

Most vehicles will not deliver enough to keep up with the draw of the fridge. There are DC to DC chargers that can act as power supplies to power your fridge when traveling, but wiring will have to be upgraded.

As far as the flame going out when driving, that is not normal, but I’ll let someone with more experience with that tackle the issue.

[John in Santa Cruz]

This is the 7 blade socket on the back of the truck... The plug on the trailer is the mirror image



Unplug the trailer, connect a volt meter between white (ground) and red (charge power) on the trailer plug, you should see your battery voltage. Start the truck and measure the same two on the truck connector, you should see your trucks charging voltage, maybe 13.6 to 14.4 volts

This may not work on new vehicles with "smart" power systems as those might not output charging voltage unless they detect a trailer plugged in... But your '14 Toyota should be fine.

[alanmalk]

Originally Posted by Tardigrade

...
I was under the impression the truck should be delivering power to the trailer but it's clear that's not happening. I'm looking for advice on troubleshooting this.
...

Quick and dirty way to see if any power is getting to the trailer:

With the truck power cord disconnected, turn on a couple of trailer interior lights. Turn off the battery main switch. The lights should go out. Plug in the truck, then start the engine. Go back to the trailer and verify the lights are on (or still off).

If "off" then get out the multi-meter and start checking the plug as suggested above.

If "on" then the likely answer is voltage drop between the alternator and the fridge. On my Tacoma/Escape 21 setup the voltage drop is about 1.5 Volts with the fridge turned on. This means the batteries are still providing the vast majority of the power to run the fridge, and the truck is providing very little. After a long drive you will find your batteries quite low. You can divide the blame between Toyota and Escape, both having skimped on the wire gauge.

One solution is new heavy gauge wire, another is a DC-DC converter. Better is a combination of both but now your talking serious $$$. The absolute best (and cheapest) is to find out why the flame blows out. That is not normal in my opinion.

[Tardigrade]

Oh interesting. The manual from the Norcold says it won't work on propane while moving so I thought that was normal. If we could get that to work it would help.

But still, the current from the battries changes 0% when the truck is running. Even if it helped a little with the battery that would be nice.

Thanks for the feedback!

[Tardigrade]

John this is a great start, thanks! I'll have to wait until tomorrow but I'll test it out.

[Tardigrade]

Alan, great suggestion. I'll try it tomorrow. Thanks!

[C&G in FL]

Originally Posted by Tardigrade

Oh interesting. The manual from the Norcold says it won't work on propane while moving so I thought that was normal. If we could get that to work it would help.

But still, the current from the battries changes 0% when the truck is running. Even if it helped a little with the battery that would be nice.

Thanks for the feedback!

I do not know much about Norcold absorption refrigerators not being able to work on propane while moving. Does Norcold give a reason why? I do know that my Dometic would blow out when I was towing, but I constructed a baffle out of aluminum to block the wind from getting to the burner and added window screen to the louvers. After that, the Dometic would stay lit while moving.

In general, most tow vehicles as they come from the factory do not provide adequate power to keep the batteries charged if the batteries are heating the 12 vdc resistance heating element in a refrigerator.

You might try packing ice in the refrigerator. I have friends with a 21 who never run the refrigerator when towing. They use the blue “ice packs” and re-cool them once they are on shore power. But that is not a solution if you do a lot of boondocking.

[MrLynn]

Whether to run with the three-way fridge on has been a perennial topic here (and on other forums). The general consensus seems to be: don't rely on your tow-vehicle to keep the fridge running on battery.

If not, then should you run on propane? Here, opinions seem to be divided: "Yes, I always run with propane on"; "no, I never run with propane on."

I favor the second rule. I worry about the 60 mph wind rushing by the trailer blowing out the tiny flame that keeps the fridge working. Folks say it doesn't; I would rather err on the side of caution. Also, many tunnels (and even gas stations) require you to turn off your propane tanks. So we leave the propane off when traveling.

We've found that our fridge stays cold for many hours. It works like a big cooler, and if we keep some frozen food or ice in it, it stays cold for quite a long time. I will admit we haven't tried it for a whole day when it's very hot outside, so there may be limits. But then, there are smaller coolers you can use, too.

So if your "fire goes out," that's a problem you need to address if you want to keep the fridge running between stops. For me, that just validates my view that propane fridges should be turned off when traveling.

If you don't agree, then you'll have to either find out why it goes off, or upgrade the wiring from your TV, as others have suggested here.

[Ron in BC]

You're right, it's a topic that's been discussed with great vigor over the years.

Since I've towed all over North America without incident or problems it's obvious which camp I'm in.

My old Dometic had issues but blowing out while travelling wasn't one of them. The one in my 21 has always worked flawlessly. I'd say do some trouble shooting because it's a bonus to be able to keep it going full time.

Ron

[SageRpod]

We had issues with the fridge not running on propane in our old, 90's Starcraft but it hasn't been an issue with the Dometics in our previous Rpod and now our Escape 5.0. I've always felt safe traveling that way however there is debate on the definition of what constitutes "open flame" specifically at gas stations. I always shut off the propane before pulling into a fueling bay. Sounds like a pain but really isn't since we usually only fuel once thanks to our large gas tank on the F150.

[iamunique127]

We travelled in the heat of last summer and even with new internal fridge fans and fridge vent fans installed the Dometic struggled to keep cold and that was running all the time, travelling or not. I wouldn’t have wanted it off at any time. I’d certainly look into why it shuts off when travelling.

[MrLynn]

One more potential hazard to consider, besides 'open flames', is the risk of open propane valves in the event of an accident: could make a bad situation much worse.

[brroberts]

Originally Posted by iamunique127

We travelled in the heat of last summer and even with new internal fridge fans and fridge vent fans installed the Dometic struggled to keep cold and that was running all the time, travelling or not. I wouldn’t have wanted it off at any time. I’d certainly look into why it shuts off when travelling.

Here’s what I have done. Others have done similar:

First post 74:

https://www.escapeforum.org/forums/f...e-21759-4.html

And then posts 84-115:

https://www.escapeforum.org/forums/f...e-21759-5.html

Finally, post 187:

https://www.escapeforum.org/forums/f...-21759-10.html

It’s still not perfect, but it does work better. I don’t worry about ruining food in the fridge any more.

[C&G in FL]

Originally Posted by MrLynn

One more potential hazard to consider, besides 'open flames', is the risk of open propane valves in the event of an accident: could make a bad situation much worse.

You can purchase a “Gas Stop” which cuts flow in the event of a catastrophic breach in a gas line. They cost @ $65 at Amazon and other retailers. They eliminate the risk of open propane valves making a bad situation much worse, even in the absence of an accident. You need two if you use the auto changeover feature on the regulator, but only one if you manually change tanks when one runs out. I have always done it manually. When propane runs out I know that one of the tanks is empty and get it filled. My reason.…..I do know people using the auto changeover with both valves open and they ran out of propane.

[DanandDaphne]

Originally Posted by C&G in FL

You can purchase a “Gas Stop” which cuts flow in the event of a catastrophic breach in a gas line. They cost @ $65 at Amazon and other retailers. They eliminate the risk of open propane valves making a bad situation much worse, even in the absence of an accident. You need two if you use the auto changeover feature on the regulator, but only one if you manually change tanks when one runs out. I have always done it manually. When propane runs out I know that one of the tanks is empty and get it filled. My reason.…..I do know people using the auto changeover with both valves open and ran out of propane.

This is already built into any newer propane tanks that any of us would be using. I don't know maybe these Gas Stop devices would be more reliable but I haven't ever heard of there being a problem with the ones already in the tank valve.

I have had this protection devise trip on a propane tank and there is absolutely no gas coming out. I had to bring the tank in to be filled and forcing gas in re set the valve.

[Centex]

Originally Posted by DanandDaphne

This is already built into any newer propane tanks that any of us would be using.

Respectfully, that's a common but incorrect misconception.

The OPD (Overfill Prevention Device) built-in to modern tanks serves to prevent overfilling of the tank but does not restrict gas flow if a regulator failure or 'open line' occurs.

Common 'portable' LPG tanks of the type we use in the RV environment lack an integral flow restricting device because there are some legitimate applications outside of our RV / BBQ experience which require very high flow rates.

However, a valve inside the 'green nut' of the pigtail between the tank and the regulator does serve as a safety device to severely restrict (but not necessarily completely stop) gas flow in the case of a regulator failure or 'open line' occurrence. It is this 'excess flow prevention valve', integral to the pigtail, which can 'block flow' sometimes when the tank main valve is opened too quickly, a phenomenon some folks have experienced much to their bewilderment.

[7Gentex]

What battery setup do you have?

Tow vehicle alternator rating?

Solar?

Do you have a DC/DC convertor? (Likely if you have lithium batts)

If so, ETI seems to default set the Victron DC/DC convertor to "power supply" versus "charge", so it would only try to "supply" current to the trailer system, though likely not near enough to run a 18 amp draw from the fridge due to wiring limitations from the tow vehicle to the trailer batts. This can be changed in the Victron app to "charge" while the DC/DC convertor is active. Even so, with stock tow vehicle / trailer wiring to the batts, you will be limited.

If not, and you have lead / acid batts, you will likely never get enough juice from your tow vehicle (with stock wiring) to run the fridge @ 18 amps without running down the batts.

Easy Answer - run the fridge on propane while towing. I have never seen a model that says not to........What model do you have?

Other Answer - lithium batts, DC/DC charger set to "charge", better wiring from TV to trailer batts

[h2owmn]

I keep a few gatorade bottles mostly filled w water and rotate them from freezer to refrigerator etc, and even in summer, had had good luck with the temps within acceptable levels.

[John in Santa Cruz]

When I had a freeway absorption fridge, I always ran it on propane while traveling. It was a dometic RMD855. When it crapped out. I replaced it with a DC compressor fridge which I always run on DC all the time. Anyways. I have more solar than the DC it draws so as long as I get some sunny days I'm good forever. My 2 big lithium batteries will run the fridge and all the rest of my usual camping workload for at least a week so I'm good there too without sun