Battery charging via truck

[neal]

My crusader 270RET has a brand new battery installed and went dead pretty fast when we opened up the camper at home. Can someone tell me if my truck should charge the batt. while driving on the road?
I started my truck up and nothing still worked on 12 volt in the camper.
Thanks,any help would be great.

[bikendan]

Most tow vehicles will only provide a trickle charge while driving.
It would take hours of driving to recharge a depleted battery.

[neal]

I thought that at least a light would work with truck running. My 2003 dodge has a 12 hot wire in the main plug for aux. batt. on a trailer. Does that wire go directly to the camper batt. ?
Is there a wiring diagram available for the crusader 270RET?
thanks.

[Bluepill]

Good video here:

https://youtu.be/FboDyLjn5sg

Many more also on youtube.


BTW, an inexpensive digital voltmeter (or multimeter) is a basic tool for any electrical system testing or diagnosis.

Originally Posted by neal

I thought that at least a light would work with truck running. My 2003 dodge has a 12 hot wire in the main plug for aux. batt. on a trailer. Does that wire go directly to the camper batt. ?
Is there a wiring diagram available for the crusader 270RET?
thanks.

Follow the wiring from the truck. Test the truck battery voltage with the engine running. As you follow the wiring, you should be within a few tenths of a volt that is showing at the truck battery. If you find a sudden drop at some point, you have found the problem area.

[bikendan]

Originally Posted by neal

Is there a wiring diagram available for the crusader 270RET?
thanks.

No

[neal]

thanks for the clarification, I will check those items.

[spock123]

You can turn your lights on your truck and that will put a little more power to your battery


Sent from my iPhone using Forest River Forums

[Witch Doctor]

You have 1 charging wire from your TV to the plug and also in the plug you have 12v hot from your TT and a ground if it's a 7 pin plug, just went through all this myself. If you keep a load on like suggested it will help keep the amps up going to the TT battery other then that once it reads your TV voltage it will drop down and get what I call only a trickle charge at best back to your TT. If you can keep the voltage output to about 14v then you would shorten the time it takes, only way I know of is to turn your headlights on I'm surely not a mechanic, but that is what I found, If I'm wrong I'm sure there's a few people on here that will correct my statement. Sorry I can't be of more help...

[KyDan]

Neal, you don't really say if you've checked for battery voltage at the truck
socket. Some trucks require the installation of a fuse in order to make the
battery lead "hot" at the socket.

While the trailer battery probably won't get much of a charge from the
truck it definitely should power the lights in the trailer if the trailer battery
is low. I've plugged my truck back in many times to carry on when my
trailer was getting low.

Take a look her to see which pin is ground and which is 12v plus--

[f5moab]

Just saw the make of truck, following information does not relate to that vehicle.
I know for a fact that late model GM trucks (at least 2013 and later I know for a fact) will increase the output to the trailer from a possible 12.5-13.1V, in what they call a fuel economy mode where the generator output is very low, to a 13.9-14.5V if the headlamps are turned On, or in Tow Haul Mode (if equipped).

[OldCoot]

I think you have to put a fuse in the TRUCK to get it to charge. Most dealers will install it when they wire the truck.

[clr]

The first thing to do is to check for 12vdc at the truck 7 pin plug. Per the diagram above you should find 12vdc when the truck is running on pin 4 of the plug. If you have no voltage there your truck was never setup for the 12vdc aux. Depending upon the brand of truck you may have to install a relay in the fuse box and or a fuse in the fuse box. In a GM truck you may have to connect the wiring harness as it does not come from the factory connected.

[Tommy Joann]

Same thing happened to me, it was a blown fuse in the truck.

[MtBiker]

My 2000 Ford pickup had a tow package installed. I noticed no charge coming from the correct output on the 7 pin. Went to the little bag that the hardware had come in looking for the wiring diagram and found two small relays in the bag.
The previous owner had never installed the relays for the tow kit.

[Tom48]

Originally Posted by neal

thanks for the clarification, I will check those items.

First, you need to ensure that the 12 volt line through your 7 pin connector is feeding power to the trailer. If you are here just hooked up with the engine running there might not be sufficient current flow to charge the battery but you should be able to test 12 volts at the trailer when the truck is hooked up and running.

The point of turning on your truck headlights is to put a demand on the truck battery so the truck alternator steps up the current and voltage available for your towed vehicle.

If a new battery has gone dead in your trailer there is probably something wrong with the electrical circuit in your trailer unless it that has taken place over several weeks.

While you're on the open road with the engine it working RPM, at best the feed to the trailer will be a trickle charger. It could take 10 or 12 hours of Road time to make a meaningful difference in the battery charge level

Best tool is a multimeter that is also a AC DC clamp meter. I need to be able to measure the current flow in or out of the battery. If the battery is disconnected, fully charged and allowed to rest for about 12 hours a good battery will read approximately 12.7 volts. Totally disconnected, a week later I would expect a good battery still read 12.6 volts more or less. The same should be true with a battery hooked up to your trailer if you have a true battery cutoff switch. The same problem keeps showing up time and time again of people under estimating the static draw of their trailer either because they don't have a cut off switch or because the cutoff switch doesn't cut everythingoff.

Short answer a good battery should hold its charge if not connected to a load. Enroute the tow vehicle is barely adding a charge to even a good battery so if you start out without a fully charged battery you're going to arrive in Camp without a fully charged battery. Possibly the biggest mistake universally made is that one battery is enough for anything. One battery should be enough to meet your needs from home until you get to the hookups in Camp. If you plan to get dry camping time out of one battery you are used will have to be very very tightly managed.

Finally if you have drawn the battery down to zero chances are very good that the battery is irrevocably damaged. I would wrap it with a big voltage charge and leave it on the charger overnight then tested disconnected voltage 12 hours later and again 3 days after that. It is still sitting around 12.6 or 12.7 you might have some useful life still left in it. Good luck

[hillsdaletc]

Not sure what truck you have but get out your operators manual and lookup the fuses. Look for the battery charge fuse, or on GM trucks look for a red wire taped back on the wire loom coming up under the fuse box under the hood. It gets attached to the battery stud on the left side of the fuse panel. It goes back to the trailer plug in back. Mfrs. do not install the charge line fuse or hook up the cable.

[furtrader]

Something almost nobody ever thinks about is the output of the alternator on the truck. If it is a standard one it will have an output of around 150 amps. If you intend to have your
truck power (12V) accessories like electric brakes on a trailer, and extra 15 or so running lights, turn and brakes lights etc. you will have to order your truck with a high output alternator, something like 200 or higher amp output. This is the reason Ford offers a 200 amp as well as duel alternators with a 357 amp combined output, not sure about GM or Ram
but I think they do also. You might think that they would be included with the big tow packages but they usually are not.

[KyDan]

Caution- thread hijack in progress!
I hear what your saying about extra load but my little ole 04 silverado has
never exhibited any signs of low battery and I've towed thousands of miles.
3 different trailers. Current one has LED marker and tail lights so less load
there but the others were all standard bulbs and never a problem with battery charge. And I run with my lights on all the time, not just at
night.

The ONLY time I had issues was with my 1st trailer which had the 3 way
refer. When that thing was on 12v cooling it sucked power. Truck nearly failed to start one time after a short 30 minute lunch stop with engine off.

Back to the original post we haven't gotten a follow up from the OP but hopefully we've
answered his question!

Happy Trails!

[TandSH]

[QUOTE=spock123;1310172]You can turn your lights on your truck and that will put a little more power to your battery

I don't accept that as a blanket true statement for most/all/some vehicles. I have also read the same about selecting tow/haul, but in neither case was there any difference in voltage at the 7-way plugs of my 2016 F-250. It might be so in other vehicles but the only way to know for certain is to check with a voltmeter.

[CHICKDOE]

I wanted to check out if there was more voltage in tow mode or with the lights on. I have a 2015 dodge ram 3500 with the cummins diesel and the heavy duty alternator. I got the same voltage measures (13.87 volts) at the 7 pin receptacle with nothing on, with tow mode on, with lights on, with tow mode and lights on.