Shore power while towing

[XCountry]

My RAM 2500 has power in the truck bed, pulling 2021 27’ GT w/ 50 Amp. We are planning some very long hauls, is it advisable to connect shore power to the truck to power the fridge, etc (but not AC) during travel?

[ROBERT CROSS]

Doesn't the fridge also run on LP?
It 'sez '2-way' in the spec's"🤔

The only time we use SP for the fridge is on the pad getting ready for a trip.

Bob
🇺🇸

[TRIPPPIN]

Originally Posted by XCountry

My RAM 2500 has power in the truck bed, pulling 2021 27’ GT w/ 50 Amp. We are planning some very long hauls, is it advisable to connect shore power to the truck to power the fridge, etc (but not AC) during travel?

I don't know the specs for your Ram but if it is like most 110 outlets on vehicles these days the amperage is too low to use as shore power or even a power a small appliance. Your GT has 12v capability for the fridge so I would ensure my 12 power from the Ram to the trailer charges the trailer battery while towing if you don't already have solar. If you have solar it should help keep the 12v batteries charged while on the road. The 12v fridge can drain a battery very quickly.

[Rich W]

You don't mention the year of your RAM but a quick Internet search shows some of the recent RAM inverters have a 400 watt limit. My Dometic Fridge owners manual says the electric heating element is 175 watts. But mine is a 2006 model so check your fridge's owners manual for the 120 AC wattage requirement.

[13013]

Good Afternoon, I too have a 2019 RAM 2500. My truck is a Turbo Diesel that pulls our 27' Flying Cloud - it too is a 50 Amp model.

There is absolutely no reason to apply any more power to your rig in transit than the 12 volts DC you provide it by having your trailer connected electrically via your 7 Way cable. To do anything more is either illegal, amazingly foolish or both.

I apologize for being harsh or offensive but you must understand both the capabilities and the limitations or your rig. Please take this response in the spirit it is intended, I want you to be able to enjoy your travels without endangering yourselves and/or motorists and campers around you.

Operating dual generators in parallel while driving is not safe or necessary given the capabilities of both your modern truck and your beautiful new trailer. The 12 volts DC provided by your truck while driving daily is enough power to keep your batteries charged between either using generators or shore power at your destination for the evening. There are probably only a few items that you cannot use inside your Airstream while in transit. In mine it is the microwave but I haven't checked the TV's or the Blue Ray player - it's a temporary stop after all.

We've stopped and applied power to the Airstream via our 2 Onan P4500i Inverter Generators (unleaded gasoline) to cool our rig and enjoy an extended lunch on occasion. It takes about 10 minutes to cool the trailer completely.

Our refrigerator, as I suspect your does too, runs on both shore power and a combination of 12 volts DC and LP/ propane. I mention my generators for this reason: Generators require fuel, which means you logically store it in a specifically designed container that must be secured in the bed of the truck by other material and/or equipment you use to enjoy your trip and perform routine and emergency maintainance. If you were to drive down the road with two generators or even one large generator big enough to power a 50 Amp trailer:
1. The heat from the exhaust could melt anything in the bed of your truck and possibly ignite your fuel can(s).
2. The carbon monoxide could potentially leak into the cabin of the truck and cause drowsiness and an accident.
3.The vibrations from the generator(s) could damage other equipment or prove annoying as you travel.
4.And finally, the thick gauge cable running from the bed of your truck halfway-down to your electrical receptacle would be prone to wear and excessive damage from being exposed to 60+ MPH speeds when it is supposed to be in place only when stationary. That cable is expensive to replace too!

In a nutshell, you are in the right spot to ask questions and I'm glad you're doing some research before setting out on your adventures. Read your manuals first, it's your investment, time, and holiday but it is everyone's safety!

Also, do yourself a favor now by replacing your stock 7 Way male connector at the front of your trailer with a Hopkins replacement connector. The OEM item doesn't fit the RAM receptacle and can lead to electrical "anomalie and gremlins" you don't need to waste time with. Trust me, the wonderful team at the Airstream Service Center did it for me - it seems to be a common issue with RAM's at least.

I wish you nothing but success!

[AnnaBelle33]

Originally Posted by 13013

Also, do yourself a favor now by replacing your stock 7 Way male connector at the front of your trailer with a Hopkins replacement connector. The OEM item doesn't fit the RAM receptacle and can lead to electrical "anomalie and gremlins" you don't need to waste time with. Trust me, the wonderful team at the Airstream Service Center did it for me - it seems to be a common issue with RAM's at least.

I wish you nothing but success!

I have a 2019 RAM 2500 Limited (diesel) as well. This part of your post concerns me. Mine fits perfectly and I’ve had no issues but..... how can I tell if this is something I need to address? Thanks!

[13013]

AnnaBelle33:

I'm glad you haven't experienced the same issue I have. I was frustrated while driving and seeing the dashboard cycle between faults on a regular basis. The faults included "No Trailer Detected" and cycled in the same order at regular intervals. My local RAM dealership couldn't replicate the issue and blamed the Airstream. The local Airstream dealer couldn't replicate the issue and blamed the RAM. It's a classic story.

I mentioned the story to the team at the Airstream Service Center and they told me that they had experienced this before. Because there is no no real "industry standard" when it comes to some of the parts (7 Way Connectors) within the automotive manufacturing world, there are slight differences in materials, connections, engineering design and of course, workmanship. Additionally, when you add in the variable of the RV dealership Technician - anything can happen.

Previously, I was experiencing an intermittent power problem to my right rear LED rail light. The RV Technicians constantly poked and prodded at the connector while troubleshooting the tail light issue. It appears that all that prodding combined with the loose tolerances of the fitment of the male connector to the truck introduced this problem.

If you are not experiencing any issues now - leave it alone. If you experience issues in the future, perhaps a wrap or two of electrical tape around the exterior of the male connector will close the gap and improve the constant electrical connection until which time you may wish to replace the connector.

I'm thrilled with the replacement product. Now I have a positive and satisfying audible and tactile response when making the electrical connection. After that I secure the connector in place with the RAM's receptacle cap (as usual).

I hope this helps and eases your mind a bit, I'm sorry to have alarmed you.

[AnnaBelle33]

Thank you for that reply. So far so good. I’ve towed from Tampa to North GA and a couple of local trips and haven’t experienced anything like that so far. I’ve owned several trucks and this RAM is my favorite by far. I’ve got a Classic 33’ and I forget it’s behind me sometimes while driving.

[Bcc75]

A little bit of dilectric grease on both the male and female connection points of the 7 way will help the connectivity and prevent corrosion.

[Fungus]

A little dab of dielectric grease in the contacts is good practice for when you park you rig for an extended period of time, too.

[tjdonahoe]

Originally Posted by XCountry

My RAM 2500 has power in the truck bed, pulling 2021 27’ GT w/ 50 Amp. We are planning some very long hauls, is it advisable to connect shore power to the truck to power the fridge, etc (but not AC) during travel?

Not enough amps

[Bill M.]

On my RAM I have to hit the 7 way with a good bump to get it to seat all the way. Then it is fine.

[albret]

Are you planning on strapping your trailer's 120V power cord to the side of you trailer driving down the road? Your trailer refrig runs on 12V battery power and propane gas. The 7-pin connector on your track powers the refrig (provided the propane gas is turned on) as you travel. In any event the battery in the trailer will provide the 12V power when the truck is turned off. You are concerned over nothing. YES, grease your hitch (not with WD40) just like you see the semi-truck greasing their hitches. That is required to keep your hitch operational and running correctly.

[coasttocoast]

A Goal Zero 3000x might be a solution for you.

[pianolaw]

I have a 2017 Ram 2500 pulling a 27FB Int'l. I experienced the 7-way plug coming loose at times and I would lose the connection to the rear view camera. At first I used some duct tape but that leaves a sticky residue. Then I discovered velcro tape and it snugs it up great and no more sticky residue and no more loose connections. I also use dielectric grease to keep out moisture and reduce corrosion.

[GeeSag]

Has anyone found a good way to run the fridge on long drive days without the propane?

I am wondering about a small inverter for just the fridge. Run only the fridge on 120 volt while driving and leave propane off at the tanks.

If the fridge is about 400 watts on AC, then a 500 watt or even a 1000 watt inverter might do the trick.
500 watt inverter is probably too small for peak amps, but a 1000 watt should draw only the 400 watts plus inefficiencies as steady state assuming the fridge is really about 400 watts.

Has anyone run thru all the numbers?

Would 400 watts steady state kill the truck alternator?

[Wazbro]

Originally Posted by GeeSag

Has anyone found a good way to run the fridge on long drive days without the propane?

I am wondering about a small inverter for just the fridge. Run only the fridge on 120 volt while driving and leave propane off at the tanks.

If the fridge is about 400 watts on AC, then a 500 watt or even a 1000 watt inverter might do the trick.
500 watt inverter is probably too small for peak amps, but a 1000 watt should draw only the 400 watts plus inefficiencies as steady state assuming the fridge is really about 400 watts.

Has anyone run thru all the numbers?

Would 400 watts steady state kill the truck alternator?

Well that is exactly what the OP is asking about doing with his factory inverter. I'm pretty sure his trailer has a 120v/12v compressor fridge though, not absorption, NO PROPANE. Something half the people responding didn't take the time to understand.
While the absorption fridge like yours uses more power then his it could work, 400 watts requires about 35 amps @ 12 volts. That is way too much for the 7-way cord to supply. Not too much for the alternator you would need to have the inverter closer to the TV battery or use heavy wires to get 12v power to the inverter. So the biggest problem for both of you is safely getting the power to the fridge without hurting your trailers.

[stevejones]

Originally Posted by XCountry

My RAM 2500 has power in the truck bed, pulling 2021 27’ GT w/ 50 Amp. We are planning some very long hauls, is it advisable to connect shore power to the truck to power the fridge, etc (but not AC) during travel?

Your refrigerator runs off 12VDC or 110 VAC. While traveling you should be running off 12VDC. Don't understand why you'd want to take your truck's 12VDC, convert it to AC using your truck's inverter (with resultant energy loss), and then somehow run that to your trailer... where I think your refer will convert the AC back to 12V (with more energy loss) in order to run. You sure as HECK won't be able to safely snake the heavy 50A cable from your trailer to your tow vehicle while running down the road.

Just run your refer off the 12V from your trailer batteries. Your truck should be charging your trailer batteries as you go down the road. If you have solar your panels should be charging the batteries as well.

Or is there more to this? (the ".etc" in your post?). Are you trying to run something else besides the refrigerator?

Steve

[mikeinca]

Originally Posted by XCountry

My RAM 2500 has power in the truck bed, pulling 2021 27’ GT w/ 50 Amp. We are planning some very long hauls, is it advisable to connect shore power to the truck to power the fridge, etc (but not AC) during travel?

All due respect, but how would you even do that?

[GeeSag]

While most replies seem to indicate just run on propane.

How many do you think of those that run their fridge on propane when traveling are actually turning off the fridge BEFORE thy get to the fuel pumps?
And then stopping yet again to turn the fridge back on again after leaving the pumps.


I am thinking of large gauge wires, large gauge quick connectors near the 7 pin, And adding to the puzzle a dc to dc converter in the TV that would disconnect when the tow vehicle engine shuts off to prevent pulling off TV battery when shut off.

Plus having a dedicated inverter as opposed to the built in inverter would allow to keep the 120 volt high voltage wiring to a minimum to avoid any 120 volt dangers of wires running through the extent of the rv in the event of an accident.


A more simple solution would be to use one of the upfitter switches in the tow vehicle to switch the fridge on and off remotely through low amperage wiring and still use the propane except when at fuel pumps.
This would be a fairly simple solution to make sure the flame is off at fuel pumps. This does not provide a way to shut off the propane at the tanks.
Not having a propane leak during an accident would be an improvement over all those running off propane while driving.

Has anyone had experience running 35 amps steady state off the alternator?


So short answer: Has anyone really answered the original post question other than Run Off Propane.