5W jacks powered by tow hookup?

[Tom]

Is it normal for a tow truck to power the jacks on a 5th wheel when the 5W is hooked up to the truck? Or does it only power the rear lights and turn signals on the 5W? The reason I ask is that we have a 5W in storage a couple of miles from our WY summer lot (no power available to permit battery charging or a battery minder). We don't own a truck, and don't plan to buy one for the 2x/year 2-miles trip between winter storage and our lot. Unfortunately, a couple of folks who have towed the 5W for us in the past are no longer available for various reasons.

I don't know if my 5W batteries will be dead &/or shot, so pre-arranging for a commercial tow could be an issue if I couldn't raise the jacks when they got there. My other option is to book a cabin or motel for a night or two, giving me time to check things out and charge or replace the 5W batteries.

FWIW one of the folks who previously tried to tow the 5W to our lot (before we got there) arrived to find dead batteries. He was kind enough to take the batteries to his lot for an overnight charge, and even took them to the local NAPA store to have them load tested. That suggests that his electrical hookup doesn't charge the 5W batteries.

Grand Design 367BHS.

 

[msw3113]

I understand that jacks are powered by the on-board battery bank, not by the truck, and not even if the 5w is plugged into a 50-amp power source. If the on-board batteries have insufficient charge, they won't operate the jacks. The 7-way connection will provide a limited amount of power to the batteries from the truck, but it may take a while to charge the batteries that way.
A "jump pack" may be able to power the jacks but I haven't tried it. I've heard of people using jumper cables to the on-board battery bank, but they'd have to be rather long to allow the tow vehicle to back under the kingpin. Or the cables could be attached to another vehicle. Unknown how much room is in your storage area.

 

[Tom]

I understand that jacks are powered by the on-board battery bank, not by the truck, and not even if the 5w is plugged into a 50-amp power source. If the on-board batteries have insufficient charge, they won't operate the jacks. The 7-way connection will provide a limited amount of power to the batteries from the truck, but it may take a while to charge the batteries that way.

Thanks, that's what I was concerned with, and figured I'd need to take the batteries to our lot for an overnight charge while we stayed at a cabin or motel.

A "jump pack" may be able to power the jacks but I haven't tried it.

I have one of those, and have used it to dump sufficient charge into a dead battery to start a car.

I've heard of people using jumper cables to the on-board battery bank, but they'd have to be rather long to allow the tow vehicle to back under the kingpin. Or the cables could be attached to another vehicle. Unknown how much room is in your storage area.

Good thought.

Thanks again.

 

[Gary RV_Wizard]

In a typical trailer hook-up to the tow vehicle, one of the 12v feed wires goes to the trailer battery bank. While the tow vehicle engine is running it would [eventually] charge the batteries, but rarely would that feeder be sufficient to fully power the jacks if the batteries are dead. In fact, if the batteries are totally dead the breaker/fuse on the 12v feeder might well trip from the high amp load (in-rush current). Even without operating the jacks. There is no standard wire gauge or fuse size for trailer plugs, so it's an "iffy" proposition at best.

I think I would plan on getting the trailer batteries charged before attempting a tow.

 

[xrated]

If that trailer has the Lippert hydraulic leveling system on it, I can guarantee you that the truck will not be enough power to operate the hydraulic pump for the landing gear. The suggestion of having long enough jumper cables to reach from the front of a truck to the battery in the 5ver might work, but that is only if the batteries in the 5ver aren't shot. That hydraulic system will pull approx. 70 amps when the pump motor is running and operating a landing gear on the trailer. I have a Momentum with the six point Lippert Hydraulic system on it, and I've checked current several times with my clamp on amprobe and it's always between 68 to 70 amp.....raising or lowering the landing gear. Hope this helps.

 

[Tom]

That hydraulic system will pull approx. 70 amps when the pump motor is running and operating a landing gear on the trailer. I have a Momentum with the six point Lippert Hydraulic system on it, and I've checked current several times with my clamp on amprobe and it's always between 68 to 70 amp.....raising or lowering the landing gear. Hope this helps.

Ah, some real data from another GD owner. Thanks!

 

[Lou Schneider]

There is usually a charging wire from a tow vehicle but it only provides 10-20 amps at most, so it would take some time with the truck connected and idling to build enough charge in a dead trailer battery to run the jacks.

Probably the easiest solution is to be ready with a set of jumper cables from a second vehicle to "jump start" the trailer battery while the jacks are being retracted. When you get to your site plug the trailer into shore power and the converter should supply enough current to run the jacks.

 

[TonyL]

When are you going to need towing Tom?
We'll be in the area but not until around July.

 

[xrated]

There is usually a charging wire from a tow vehicle but it only provides 10-20 amps at most, so it would take some time with the truck connected and idling to build enough charge in a dead trailer battery to run the jacks.

Probably the easiest solution is to be ready with a set of jumper cables from a second vehicle to "jump start" the trailer battery while the jacks are being retracted. When you get to your site plug the trailer into shore power and the converter should supply enough current to run the jacks.

In reference to the bolded section of your comment.....That won't happen. Most of the Grand Design campers of the size that his is, and even the bigger one like mine, the stock converter/Charger is a 55A unit. The Lippert hydraulic motor/pump for those units will regularly and normally pull right at 70 amps and the Converter/Charger is simply not capable of providing that much power to the pump motor.

 

[xrated]

Ah, some real data from another GD owner. Thanks!

You're welcome.....glad to help.

 

[Tom]

When are you going to need towing Tom?
We'll be in the area but not until around July.

A big thanks Tony. We'll be in Star Valley first week of June. We'd normally be ready to head out before that, but our uke band has a couple of concerts June 1 & 2. Chris is itching to leave (already packing), but she also has to video our show.

 

[Lou Schneider]

In reference to the bolded section of your comment.....That won't happen. Most of the Grand Design campers of the size that his is, and even the bigger one like mine, the stock converter/Charger is a 55A unit. The Lippert hydraulic motor/pump for those units will regularly and normally pull right at 70 amps and the Converter/Charger is simply not capable of providing that much power to the pump motor.

But it will start charging the batteries at that rate or close to it when you plug it in. Wait a couple of minutes for some charge to accumulate in the batteries and they will add the extra 15 amps to supplement the converter's output. And it's not an either/or thing. 55 amps won't stop the pump motor, it will just slow it down a bit.

 

[xrated]

But it will start charging the batteries at that rate or close to it when you plug it in. Wait a couple of minutes for some charge to accumulate in the batteries and they will add the extra 15 amps to supplement the converter's output. And it's not an either/or thing. 55 amps won't stop the pump motor, it will just slow it down a bit.

First, it would take more than a couple of minutes. Secondly, it's pretty much a moot point anyway because Tom stated that they have no power out there to utilize for the converter/charger or even a separate charged to be plugged into.

You hit the nail on the head though with a suggestion about having a "second" vehicle there to use some jumper cables for the camper, until they can get the trailer to their lot, which I am assuming has a shore power hookup. And of course is also assuming that the battery in the camper has not died for good and/or beyond recharging. If that is the case, then that battery would need to be completely disconnected from the trailer, and the jumper cables from the second car or truck be connected in it's place....ideally with the motor running on the car or truck.

 

[Tom]

You hit the nail on the head though with a suggestion about having a "second" vehicle there to use some jumper cables for the camper,

until they can get the trailer to their lot, which I am assuming has a shore power hookup.

It does.

And of course is also assuming that the battery in the camper has not died for good and/or beyond recharging. If that is the case, then that battery would need to be completely disconnected from the trailer, and the jumper cables from the second car or truck be connected in it's place....ideally with the motor running on the car or truck.

That's what I've been thinking.

 

[Hvactech]

Would a solar trickle charger work over the winter ?
You could start takeing them with you when you put the rv in storage.

 

[Tom]

Would a solar trickle charger work over the winter ?

The 5W is in covered storage for the winter, so wouldn't get much solar.

You could start takeing them with you when you put the rv in storage.

I might start taking them back to our lot (2 miles away) and put them on a battery maintainer in our shed.

 

[Tom]

A friend visited our 5W in storage today and confirmed the batteries are shot, which was what I was expecting. I called the Napa store in that town and purchased a pair of replacements which someone will pick up for us tomorrow. The guy will also move our 5W from winter storage to our lot.

Thankfully, I received a text and phone call from the guy who used to tow our 5W, but can no longer because he now has a gooseneck hitch in his truck. He was kind enough to hook me up with his friend who has a 1 ton Dodge truck with the right hitch.

 

[gwinger]

I always pull my battery when the trailer is in storage. I keep it on a maintainer in my shed.
I doubt is one of the small jump packs would have enough power to use for the jacks. They are not designed for prolonged high amp use.

 

[Tom]

I always pull my battery when the trailer is in storage. I keep it on a maintainer in my shed.

That's what I'm going to have to do going forward, starting at the end of this season.

 

[Ray-IN]

I don't know about Lippert brand(read owners manual), but HWH brand requires close to 13.5VDC+stated amperage to power the pump motor. In a MH HWH says to have the drive engine running or on shore power, with good batteries.